I loved Voyager very much and Jennifer Lien too, but I understand why the producers do not renewed her contract. The character stuck and wasn't developed very well...I don't know which fault it was, but seriously...it was time to change something...and sorry for it: but Jeri Ryan's character was much more intresting (I mean not the hot appearence of her).
The strongest and best characters are Janeway, The Doctor and Seven of Nine. On Average: Torres and maybe Tuvok. The weakest are Kim, Kes and Paris (more because of bad actors).
What about Chakotay, but to address the point actors work with what is written. If a character isn't developed whose fault is that the actors or the writers?
Now you could possible argue that the writers went with the stronger actors, but could that mean they cast the wrong actors?
but on the other hand if you're a writer, will you be giving your best stuff to someone who goes out and publicly bashes you?