We have their word for that, as opposed to any appreciable amount of feedback to actually prove it, other than the token "yes we listen" line repeated every few months.
...
And how would you expect any company to provide proof ?
Should they bore you to death with how they discussed 'your solution' and discovered that it was flawed or simply not suited to their idea of how their game should work ?
Should a company really reveal all its internal design so you can feel that they 'listened' whenever they mention something you thought of ?
What if they themselves thought of your idea ?
How would you respond to that ? I'm sure plenty of idiots would accuse Epic of 'stealing their idea' instead of being happy that a company was thinking like they were.
A "token response" is all a company can do.
If you want more then you should also be paying the company more than a few cent ...
Perhaps you should try creating something yourself and see how difficult it really is to manage a community.
Such things are only ever 'easy' if there's a really small number of 'fans' (like 10).
With a few hundred 'fans' it becomes a fulltime job for several people, especially if you're looking at a world-wide fan-base like international companies have to.
Not responding to posts in a forum is the most practical solution.
Besides ... would you rather have them waste hours posting 'thank you'-responses instead of having them use that same time to implement and test working solutions ?
Even god has not enough resources to manage the people on earth ...