WotC Fails to Credit D&D Co-Creator.

[finarvyn]

But I can see their point of view: If they credit Arneson, what about Don Kaye, or Jeff Perrin?

I would say that the big difference is that Dave Arneson's name does appear on the original 1974 product and neither Don or Jeff's does. Whatever the feeling are after the fact, it remains true that in 1974 Gary thought enough of Dave's contributions to give him co-author credits at the time.