It kind of just sounds like you take her leavig personally. I would not be happy if my favorite character was written off the show either but I definately wouldn't assume it was a personal thing. TV shows live by their fans. If they don't have fans, they don't have a show and they don't have money. So it really makes absolutely no sense that they would purposely do something to piss off their fanbase.
There are reasons why I think that episode was a "finger" to the Kes fans.
There was a campaign going for having Kes back as a regular character and what I know, those in charge knew about it.
Faced with that, they had some options.
The first option was to simply do what the fans wanted and simply bring back the character.
The second option was to ignore the fans and their request for having the character back. They could also have made a statement why it was impossible to bring back the character in that case.
Instead they came up with a totally horrible story in which the character was totally destroyed and humiliated. Just as if they thought: "You wanted your favorite back. Well eat this, you scum and don't you dare to question our decisions again because we are in charge!"
There was no point in coming up with this story at all. It had no impact on the ongoing Voyager story itself, it was no part of any arc or something like that and why bring back a character which they had done everything for three years to make the viewers forget.
It was just rude and offensive.
And when they realized that the episode wasn't well received by the fans, to say the least, there were no apologies, no explanations or any attempt to correct what they had done.
And I don't think they cared about the fanbase either. It was the end of season 6, the next season would be the last and they were starting to prepare for their next pet project "Enterprise" so they were just phasing out their efforts for Voyager.
Not to mention that they did "show the finger" to the fanbase one more time when they insulted the J/C-ers with certain events in "Endgame".