I caught most of Stargate: Infinity's run on its original airing; it also happens that at the time I was somewhat acquainted with the writers of a couple of the episodes.
It's certainly accurate to say that S:I was very much sideways to most of mainstream Stargate continuity, but the Stargate universe is big enough that that in itself wasn't a big problem for me.
My problem was with the animation/visual design, which came across as cheap, stiff, and completely wrong for the material. As I recall, it was screamingly pastel throughout, where it badly needed to be higher in contrast and much, much smoother. I don't blame viewers for being frustrated and disappointed with the show. The trouble was that the animation, both in color choice and general quality, was so far out of sync with the writing that it actually got in the way of the storytelling.