It's ok saying that they deserve their say etc...if you are not targeted by them.
Say you have a predominantly asian area and your MP was a BNP member, how on earth would you feel??
Also, when does it not be ok for them to have power, when they get 5 seats? 50 seats? 326 seats?
That aside, they are notably lazy and rarely turn up for their council duties, so hopefully not an issue.