Now that's not to say that editing credits isn't worthy of any acknowledgement for the work, but... in comparison to the point accumulation just from writing up the actual game article, it seems a little out of whack. This little oddity first occurred to me when I myself went around editing classifications for voice actors.
There are a lot of unclassified credits for voice actors on the wiki as you would expect, and when you've got individuals such as Steve Blum, where like half of his (staggeringly huge) portfolio was unclassified, the points very quickly started to add up. Hell, as you can see I'm even the top editor on the page! Despite the fact that pretty much all of my contributions have been via the credits, which frankly seems unfair.
For something as simple as credits, you should basically get like a single point per credit I'd say; another for potentially filling in some miscellaneous details per credit. So then even if you do happen to single-handedly fill out the credits with every programmer, artist, and janitor involved with the development, you'll still only perhaps find yourself with like... maybe 300 points at most. Otherwise it at the very least seems like a system that is potentially ripe for abuse. And again while the work may be boring and time-consuming--as I can speak from experience--it shouldn't have the possibility to completely overshadow any and all other such contributions on a page.
Also, there should be a ''type'' to show you've edited credits at that, much like how it's distinguished from Game Overview when you're editing, say, a game's Release details.