I don't blame Bill Shatner for playing Kirk in Generations. It is not his fault that Kirk died. Blame producer Rick Berman. According to Bill Shatner, Berman told him they were going to kill Kirk with or without Bill Shatner's participation. So even if Shatner refused to play Kirk in Generations, Berman would have hired another actor to play Kirk and have Kirk die anyway.
Navigator NCC 2120 USS Entente
/\
I highly doubt they'd hire someone else to play Kirk, no way. They'd most likely just refer to him as dead or something in the film.
And, again, it's not the fact about Kirk dying (even though it was incredibly unnecessary), it's the WAY he died that was awfully executed.