I'm quite familiar with the Rom Hacking forum as I joined PC to showcase my hack four years ago (it was terrible...lol) and from what I've noticed there back then, many people joined because they wanted to make a hack themselves, inspired by many of the popular hacks out there (think of Shiny Gold, Light Platinum, Ruby Destiny, etc.) and the vast amount of tutorials available. Really, there were over 5 pages of tutorials in the old days whereas here there are...maybe five tutorials? I can't really remember seeing over five tutorials anyway.
In short, because of the great hacks people become more interested in the section. We have a few great-looking games too, but most of them aren't playable and so won't really get the attention of most people. The complete lack of a tutorial section (true, there is the PE Wiki, but seeing some threads in the PE section, I don't think all people know about it yet) doesn't really help either.
Anyway, that is what I think, it may very well be not true, but still, it is possible ;)