Depends on the focus group. Some are put together too establish that a product is wanted. Those are junk and useless. Others like this are designed to tease out trends and their accuracy is very valuable to the companies that commission them.

Uhhhh, in general this is true, but in this particular scenario they have a stronger incentive than almost anyone to understand true preference shifts created by these drugs.

It doesn't mean they end up with the correct findings, but they are absolutely incentivized to try to produce correct findings.

Lazy and inapplicable heuristics are not legitimate insights.