A composite of EVERYTHING from everywhere in DB of Goku would differ greatly. It would have Xeno Goku and whatever Low 1-C (that sounds like wank) stuff, plus all the abilities from everywhere he is from. If we're comparing it to main canon, the Composite Goku would be far more powerful and way more haxed, with new abilities, etc.
What is specifically wrong with having Composite Goku, ignoring all the implications about other requests and the arguments that appealing to the fans is a bad thing?
It's not favoritism. It's actually a far more convincing case than every other Composite argument there is, that isn't Link from Zelda. Composite Ryu would only have, like, 3 games and some anime to Goku's hundreds of outside media appearances.
Every character in fiction being Tier 2 is too absurd to be even exceptable for hyperbole. Solar System stuff at best for all of fiction— and even then, it's usually just stuff like Naruto getting Country Level far earlier in the series based on some animations from video game special moves. And even then, that's if you choose to get Composite EVERYTHING.
This is an indexing Wiki and an online database which would imply that this website can store tons of information. If there were arguments like, it would take up too much space or data, that would make sense. But how can a database like this do its job if they refuse to store very similar copies of information for that similarity, but then refuse to use the more rational method of compositing everything not canon and canon into one profile?
The argument that Composite Ryu even deserves to be on here because of Composite Goku's existence is like comparing a businessman to a King. Goku is the exception because there is SO much material for him. Characters like Goku, Luffy, Mario, they deserve Composites because of the massive amount of information on them.
If not a composite profile, a mock profile blog like the one Kep made for Composite Pokémon humans? It took just as much, if not more research to construct research for that blog to even be made, i'm Sure.