Heh. I must be projecting my own biases a bit.A little of both actually. The bulk of the people who complained were doing so from the position of it not filling the Eberron artificer's original role(s), but there was a fair amount of complaint centered around it being too weak and actually making your character less effective.
UA also did offer the Favored Soul as well, and that was (generally) well received.
Right, for some reason I got it in my head that that article wasn't UA. Probably because it wasn't presented so much as a playtest thing as a "behind the scenes" thing with a pair of worked examples in it.