Naw, a legit strategy is draft on the straight, pull out, pass, lead the other car through the apex, let them draft, let them pass, and so on...
Bump drafting is 1 car pushing the other literally. It's not something to ashamed of, it just annoys people that are more devoted on good driving practices, and fair play.
The SCCA sanctioning body will revoke anyone's race license for any class for pulling that stunt in any other league other then Nascar, that is if they are caught doing it. It is in the rules, and forbidden, not to mention dangerous.
The rule covers it like this "intentional contact with intention to gain position by means of an unfair advantage." (sorry the SCCA loves to sound like lawyers, everything has to be specifically worded or people would try to get out of race infractions by some technicality lol)
Besides, people that bump draft usually are the ones blocking or crashing others, because they don't have good sportsmanship skills, if they did, they wouldn't be doing that. I'm not singling anyone out though, that is just from my own observations.
It's an ethical thing, whether you believe it or not. To me it's just the wrong way to develop good driving habits. Jus sayin.