All it takes is a couple of loudmouth trolls to set a negative tone on any forum. KVR's massive popularity assures their numbers will be greater there than at any product-specific forum. So yes, you are going to see posts there that seem to suggest "they hate SONAR", but they always originate from the same bunch of grumpy posters and do not actually reflect a majority opinion.
And at risk of being accused of membership in some "brigade"

, no, there is no subscription and never has been.