to me its really just a matter of allocation of resources, basically how can one use the resources at hand to make the most money. just think theres a ton of new developers on here like you said but what is the likelihood that one will actually make a game and sell it, chances are pretty low. now of those that make and sell games how many do you think will become a hit? not many, and they wont make nearly the amount of a AAA game. so do you allocate someone to answer questions for people that probably wont pay off for you or do you instead hire more marketing people to sell games and get more AAA companies to use your product. AAA companies products are almost guaranteed to sell and they get more support, that support many times come in the form of engine modifications which eventually gets integrated which enhances the engine as a product. long story short its more reliable money and good business. now i admit there could be resources allocated to both fronts but epic is also in a time of growth keeping them busy id imagine with fortnite so who knows what will come in the future.
now as for some of your other points. when i say its free i just mean that its free to use and learn until you sell your product, of course they arent giving away their product but it is a good way to get people learning their product. ok i cant articulate that point well. speaking of articulation, the point about some questions not being explained well is just a for instance case, while many questions are articulate many are not, and in some cases the asker thinks they are explaining well but they aren’t. ive answered many questions that the point was lost in google translate. some questions are just lost in the mix too, for instance theres been 4 pages of questions in the last 12 hours (many are spam and fortnite). personally i dont come on here everyday so its easy to miss things. as for incentives there used to be some badges and things but those seem to have gone with alexander.