I don't believe characters were intentionally ruined but writers/producers don't always have an accurate reading of what fans will find entertaining. Not only were Kes fans not happy with "Fury" but as mentioned above the book "Before Dishonor" made many unhappy and don't even get me started in this thread about my anger regarding "Endgame".
Yes, I get peeved too. I refuse to be egged on about it though.
Well I understand the fans would be upset, yes the Kes fans.
Still, was it always best to always have Kes to look weak all the time. The reson people do not like Kes was the idea she was to passive and let others make the rules.