Sam can do alright, but its in a similar position to blm: be really damn good at the job, or don't do it.

Other dps jobs have at least some kind of utility to bring to the table, in case they aren't extremely good at damage so they're given a bit of leeway. As a pure dps job that brings nothing unique to the table however, you NEED to be ahead of everyone (and by a good margin), or they will notice you fast.