They sound like the exact opposite to me.
I guess I don't even know what mark/smark/smart means anymore...
Anyways, in regards to the stunt itself...I didn't really find the match or the jump all that memorable or exciting. I'm sure the WWE is going to try to *make it* memorable by putting it in video packages and commercials and such for years to come, but at the time, it mostly just felt like an expected moment in the match...and there wasn't anything particularly creative about it.
Although Shane is very daring, I agree with the opinion that there are plenty of guys backstage that would likely do this, if only they were given the allowance. They didn't allow Dean/Brock to go all out but the bosses son gets to take this crowd-pleasing bump...for essentially the second time.
As far as "why" he did it...I mean, is it wrong if they guy wants to actually put on a great match or moment for the fans?