My problems with bloodlines as a judge are twofold:

1. Taking bloodlines on top of a 20-level build are problematic for the same reason that level adjustment is problematic - you're essentially getting extra levels for free. While in a game that would be mitigated by periods where you were under-leveled compared to the rest of party due to spending XP on bloodline levels or LA, in a contest like this, it's basically just free levels when compared to other builds.

I'd have far less of a problem with bloodlines if they were taken as separate levels all their own, such as we saw Briggs do back in the Shadowblade competition - Gotterdamerung submitted a Binder 7/Shadowblade 10 with three bloodline levels, but because he was essentially "paying" for those three bloodline levels by submitting a build three levels short, it seemed fair.

2. There are so many mechanics that are just broken to heck and back by bloodlines. In particular, they interact in wonky ways with initiating and pact magic classes, and they let you break skill caps earlier than the game intended you to. Taking a bunch of initiating classes and then bloodlines to bootstrap your initiator level so that you can still squeeze in 9th-level maneuvers on top of the SI, or a level in binder and a level each in, say, Anima Mage, KotSS, and Scion of Dantalion so that three bloodline levels give you a +12 boost to their effective binder level, is so cheesy that I would have to slam any entry that even hinted at doing this.

Like every rule, there are exceptions - the aforementioned Briggs used bloodlines and still managed to nab the gold, gaining enough points in other areas to make up for the elegance hit he took for using bloodlines. But expect at least a minor hit for using them all, and possibly a major hit depending on how you use them.