I think you have it there it's the marketing that really drives a lot of this anti Drift feeling, the way he was promoted, along with the rumours of a new Toy based on the IDW left many with the Impression IDW regarded Drift as the coolest thing ever to happen in Transformers. It feels as if Drift is nothing more than a marketing ploy to draw people in. Perhaps he would have been more welcomed the fandom had spotlight Drift came first and then he appeard in AHM.
And as far as Drfit being a focal point for some of the dissatisfaction with AHM, yes I'd agree that to is a factor. To me it feels like the hugely diverse TF universe has been reduced to just the favoured cast of Geewun, and instead of seeing the odd cameo, and even a little development of any of the characters from the later years we instead see Drift, replacing all of them.
Ultimately though the Drift spotlight that will make or break the character, and I will be getting that spotlight because believe it or not I and I think everyone else would like to see Drift become something, up untill then though and we get something solid I suspect the Drift bashing may continue.