I really don't see why. DotArank had way more active players when it was a channel on eurobattle.net, or even on Northrend (with its limit of players per channel).
DotArank should just find its place in D2 right now. You can already see that D1 community is dying out (very little tournaments, less than in HoN; no high level leagues) and RGC subsequently. Especially as it is now - with ddoses, kid/hacker admins, sign system that encourages fast games instead of quality games, points system that favours channels that have many games a day.
That's just what I think, you may not agree, but I remember times when DotArank was better off. And it wasn't thanks to "amazing platform", strict vouch system, good rules but players, friends, community itself.