I absolutely agree with you on marketing, and the marketeers are either treating us like idiots, or they don't have much of an idea about what Atmos is or should be themselves.
There were two major needs for Atmos, certainly in cinemas anyway. Dolby worked with studios and mixers to try and find a way to make every room, no matter what size, to convey an audio mix more accurately. The problem for the mixing studios was that movie mixes for 5.1/7.1 were being done in very highly specced mixing booths using top quality monitor speakers and amplification which was specced to work in that mixing room - How to translate that into a 1300 seat cinema where the surround speakers on the back walls are about 5 times the distance from the front speakers of the people sat in the front 3 rows and outputting half the volume of the fronts, and the bigger the room gets, the more disjointed a sound that has to travel from, say, front left to back right will become - Fine in a small room, but lost in a premium large screen cinema. So what you do is that you spec that you have enough speakers in the room which are angled in a way that provides no less than 30 degrees of coverage from each speaker, again no matter what size the room. Each speaker is timbre matched and level calibrated so that sound that has to travel from front left to rear right can now do so perfectly smoothly for every seat in the audience, not jut the people in the reference listening position. So now, instead of having a sound that starts in the front left speaker and ends up in the back right with a big gap in the middle, you use an object to move it smoothly from front left to back right, passing through as many overhead speakers as it needs to depending solely on the size of the room with no gaps in its travel. The system can be scaled to any size room and your audio mix will be conveying the original intentions whether there are 3 seats or 1300 seats. You really can fool the senses into thinking it's real with the right content. I've noticed a number of times that the sound of rain in a movie coming from overhead speakers actually makes the room feel like the temperature has dropped. It's spooky.
Which brings me onto the second requirement - Headroom. Movies have been getting louder and louder for years - This is down to the studios and mixers and is a practice akin to the audio loudness wars which do now thankfully seem to have abated, but unless a cinema is diligent with checking for comfortable listening levels and doing a practice run of each movie before it is played, you can be left with ringing ears at the end of a movie. The days of everything in a cinema being played back at reference level 7.0 are long gone because it's just too loud for the majority of todays movies. But MANY cinemas amplification and speakers are just not specced well enough for the rooms they are installed in and when trying to reproduce the levels of transients and louder passages, the amplifiers are running into clipping and speaker coils are overheating and distorting which all results in harsh, uncomfortable sound. ALL Dolby Atmos cinemas are commissioned and approved for installation and every piece of equipment on the reproduction end of the audio chain MUST have enough headroom to allow for 10% over even the loudest possible reproducible sound through that system. This guarantees lower distortion and better dynamics. More speakers and amplification channels also help here because you are not stressing each individual component anywhere near as much to get to the same overall level in the auditorium as you would with a standard 5.1/7.1 system, so even more headroom available.
Of course you still have the problem that if the movie was mixed too loud and has been compressed, squeezing all of the dynamic range out of it and your cinema has not been careful to adjust the playback level accordingly then you're still going to exit the cinema with your ears ringing, but a good cinema will ensure you're hearing that movie in the best way possible. A good Atmos mix should do exactly the opposite of the problems you have with it - For me it's not about the loud explosions and deep, floor rattling bass - It's all about the subtleties. Those tiny little sounds just audible out of the background and localised in one place, coming from a position you can pinpoint somewhere within the auditorium with extreme focus and the really creative stuff e.g going back to the fairground scene in 'Us' as the daughter is walking down the steps onto the beach and the thunderstorm is starting off in the distance - listen to the way the sound of the fairground ride is not only accurately placed as the camera pans around the girl, but how it grows into this sense of menace that she's about to get herself into trouble as she walks into the darkness, counterpointed with the clap of thunder coming in onto the shore. That scene is made by those sounds.
But on your point about the studios playing catch up to the technology, I totally agree and the same is true with Atmos mixes. Some mixes seem to be there for no other reason than getting a badge in your credits, Disney's content generally seems to go this way and much of the time I cannot tell the difference between the 5.1 and the Atmos mix, but you get a good one that's had a mixer worth his/her salt and the results can be totally breathtaking. For me, Gravity is still the reference Atmos mix. Glenn Freemantle won an Oscar for it and it's easy to tell why. There are times you feel like you're spinning around inside a space suit in the scenes with the satellite debris flying around. That has to be the most involving cinematic experience i have ever had from an audio point of view. I thought First Man was incredible too. A dialogue heavy film in many places but a perfect mix of low impact but very clear dialogue scenes with all out, edge of the seat, intense battering scenes in the rocket which were absolutely gripping.
The jury is still out for me on the home version of Atmos as it doesn't seem to be following the same specs that it does in the cinema and there seem to be too many compromises being made which I guess is down to the individual manufacturers' implementations but maybe that will improve over time, but even so, a domestic setup doesn't really require the levels of power to fill a huge room convincingly as cinemas do so it's never going to be such a big jump.
I hope you enjoy Darkest Hour.