Most of the people contributing to both TSR and MTS do not see a dime for their contributions. So why mock any of them? Just because you don't think you should have to pay for content really does not justify trashing people who contibute to any of these sites.
While 'no statue has ever been put up to a critic,' ... anyone can profit from 'negative feedback', free or pay. Paysites just deserve more of it because they happen to be charging for the crap they make, and any product is subject to such a 'review'. We can't be all nice to every single person who tries to make content. Quite a lot of it will suck. TSR (or other workshop based items) suck more as a general rule because the program attracts anyone who wants to make something 'easily', and so, you get more amateurish non-recolorable crap than with the more complicated (but better) free tools that seem to scare most people who want to make things away. There's a lot of free sites I won't get content from because they use the workshop.
And if everyone was told their stuff was wonderful when it was shit, we'd have nothing to work with but shit, and no one would be happy even if they tried to be nice to the creator who sucks.