Sorry for the late reply. I hate typing on my phone / tablet and wanted to wait until I was at a computer. Basically, our dex is terrible and doesn't give a lot of the information that a lot of competitive battlers (including myself) need. Our movedex doesn't list any information about how to get a move (or even generation) making it hard to tell at a glance if it's legal or not. You have to click through to type too which is kinda annoying. There's a lot of us who just use Veekun over Smogon because their dex is better for both competitive and non-competitive players.
We're also not a business so I see no reason we shouldn't link to Veekun. They don't have analyses. We're not competing with Veekun. They have info that is useful to our users. And it's more accurate. We have a lot of issues with our movedex.