I was shocked that our team won one at Dragon Con, audio drama. We were just a new group with just our 2nd episode, (zero funding). I haven't a clue who was funded at the time or not but I see a lot of audio groups now that are doing some type of social funding. None of the entry rules even had anything written about funding or if you're a professional group or not.
On the fan film side, Hey if you take 2nd place to another self funded group, it's like lets have a beer and talk about our win next year but if you're outspent 650 to 1, you're never going to be in it. Down the road perhaps some of your talent moves on to more funded groups, maybe someone is less interested to join up with your group. Really this effects all the fan film productions.
Ultimately taking home an honor every now and then means you're doing something right and it earns a little attention to be able to place it on your web pages.
I'm sure the conventions simply have never considered it. It's probably in their interests to attract the bigger names to draw more people in the door. Just a thought, even Boxing has weight divisions.