Why not? Probably the cost of these occasional bans are nothing compared to the reach of the ad network.
(Not that I recommend using it. I recommend the old fashioned ways of knowing where your banner ends up. And make sure it doesn't become one of 344 on some random site. So build partnerships, etc. Yeah, it sucks, it's work.)
You're arguing with an "average return" but as a single person you only play once, or in any case a small number of times if you're willing to sign up for new accounts. So the variance of your results, paired with the impact of an unfavourable outcome, should probably figure into that decision...
