Weather market BS or not there are some sound engineering reasons why thicker it better (get your minds out the gutters). In theory, it should give a better-pressed grove as there's more material to displace/emboss. Ie the opposing sides aren't pushing on one another, which can be a problem when anything pressed like this is made too thin.
And deeper groves should lead to a longer a lasting record with less chance of scratches being a problem. But there are downsides thicker will mean more brittle and less tolerant to torsional stresses, and the reason you see more warped heavyweight vinyl is that it takes longer to cool and the pressing plants don't provide that some times, being handled too roughly just after production.
I don't really buy any old stuff/remastered stuff all fairly modern, older music just isn't my bag but I do have one 1 really good remaster on heavyweight coloured vinyl (HMV vinyl week edition), DJ shadows entroducing and it sounds superb better than the CD i have from the 90's. So not everyone has bad experiences, and at the end of the day if you buy modern music it will more likely than not come on 140gram and above. I would say its not about sound quality, more longevity and collectability (which is another prickly subject). At the end of the day buy what you like sound quality is subjective at best another mans sweet is anothers bitter.