I think that some people who complain about rewards for scenarios, also underestimate the simple desire to brawl.
Open RvR takes a loooong time. There is a lot of orchestration, especially for the keep lord, and at the end of the day your guild leaders are going to be critiquing you and coaching you... And all in all, it's a good long bout of managed chaos. What would a brawler say to that? "Fuck the management, give me chaos!"
A short and dirty fight, someone walks out calling themselves the winner, the other walks out pretending their not the looser. Both have stuff to boast about, neither much gave a damn who was on their team unless they were obviously pulling their weight. The more the merrier, but the only thing better than even teams, is a win against a bigger team. And at the end of the day, it ain't about whether you win or loose, it's that you cracked enough skulls in the process to keep a hospital open for a few months.
PQs? A bunch of people taking on the sure win against a bunch of little guys, then ganging up on the first guy to actually put up a fight. Brawlers would much rather take on a situation where they could loose, whats the point in fighting if you already know you're gonna win.
Of course you don't have to be a stereotypical brawler to enjoy brawling, WAR just makes easier since you don't loose anything, like teeth for example, for your effort.
I'm not saying that's the whole reason, but it seems to me like a whole lot of bloggers have just ignored the possibility that some people might honestly enjoy scenarios much more than everything else. And not just because it's an easy way to grind out that next level.