I mostly see people trash-talking 4.3 because there's no direct upgrade path from 4.2 (and thus some effort is needed to make the switch) and because development has rolled on forever which created the wrong impression. If there's a factual problem (not an opinion problem) it needs to be reported.
The missing upgrade path seems to be a small issue.
The switch from a releasecentered approach to an agile aproach spawned a lot of side effects.