I suspect that is just a theory and the ones running the KS see this as an opportunity to make some extra money, just like any shop carrying several products would.
On top of that I see that as a distraction to their main product they should be focusing on, because now all this ‘nonsense’ eats up time and attention too.
I do not begrudge them offering a set of dice and a handful of other stuff, but if your list of addons exceeds that, then I stay away because as far as I am concerned you lost track of what is important, and I am not interested in backing something like that.
Now, this applies to TTRPGs, for board games there might be a reason for a few more addons, but there too I would be reluctant to back one that goes overboard’ with it - but I do not see me backing board games anyway