I really don't know why you wouldn't use one. Same goes for PC's - people spend thousands on our equipment but not $5 on a surge protector.
That being said, I run my tank through two APC UPS's and I use a power strip / surge off of one of those just for the extra outlets. I've never had a place with enough outlets to run a salt tank on their own.
In my old house, my tank had its own breaker. I would now, but I don't think the LL would like me doing that.