Iguess this is one of those, "most of the time but not all the time" situations when its been pretty common for KS to release once a year, so customers have equated that to "Buy the maintenance, and I get the next major release for that price" sort of thing. Maxon does the same with Cinema 4D. So, now that there is the time that KS 11 will be released outside that 12 month window, users are feeling cheated out of their "free" upgrade, even if the fine print says otherwise.
If not the "free" upgrade, might want to reiterate what people are getting for the maintenance contract?