Yes, advertisers will be scum no matter the medium. Side point: can you imagine being in an industry that produces product that people actively and energetically strive to AVOID? How depressing . . .
Flash will never be on the iPad because of what I said earlier, but also because of what Steve Jobs said at the time: Apple does not want to give control to some third-party company. Even if you had a switch to turn Flash on or off (which seems to be the party line nowadays among the Flash crowd), it would still give control to Adobe. Every time they updated the technology to enable some new goodies, Apple would depend on Adobe to make the update available to iPad (and iPhone) users. If Adobe was in a snit with Apple about something (hey, it's happened), they could delay the release. At that point it's Apple who would get flooded with complaints. It's just a potential mess that Apple does not want.
If Flash was going to be the only way to get things done in the future, Steve might have to give up that control. But Flash will be replaceable down the road, and Steve is walking down that road already.