I'm not convinced that meals are the issue. Payments/kick-backs are the issue. Meals are an exchange of "please listen to me for 30 minutes talk about our {product/solution} to these problems", and anecdotally, it's a time when these groups can question/challenge their product. I work in software, and I will listen to a vendor talk about their product for a "lunch and learn". It's a time to also get your questions answered amongst your peers.
> anecdotally it's much more pervasive in those groups.
I feel like that needs a source, but I know you mentioned it's an anecdote.