I don't think you could really compare Oasis to Pearl Jam; more Oasis to Nirvana if at all. Try and bare in mind first of all that Pearl Jam were of a time that accepted them, and that the arrival of Oasis neatly overlapped their demise so that it looks like the latter caused a revolution, saving us from the tyranny of flannel shirts and long hair of the first. Unfortunately for Pearl Jam, all bands of that "grunge" thing are treated predominantly with disdain nowadays except Nirvana, who are still mocked most of the time. I think what you say about Oasis getting people off their feet in pubs and clubs is because they are culturally significant at the moment, and have given an identity to people and a time; the same as Nirvana. Pearl Jam did not.
The battle of the singles really shows how important the Britpop thing was as a cultural phenomenon in the UK, but now look at other britpop bands: Blur, The Charlatans (move-overs from Madchester), Ocean Colour Scene et all; all in obscurity, except Oasis, even though all those bands would have gotten people off their feet in clubs 10 years ago. The same could be said about grunge; 15 years ago all those lost grunge bands like Pearl Jam and Mudhoney would have had people spilling beer. Nirvana have survived barely (well, Kurt's the biggest earning dead rock star), and of course Oasis are still going but either way both still have a massive cultural appeal and are part of history now. Of course Noel and Liam didn't fall victim to exploding head syndrome, and Nirvana were actually cared about on an international level, whereas Oasis are really only cared about in the UK but the similarities in cultural identification are visible.
From what I know about Oasis and America, even though they have not broken America bands and musicians like The Killers and Ryan Adams site them as majorly influential. On Ryan Adams's album Rock n Roll the influence is almost palpable. To be honest, I think that's a good way to be; influential but out of the spotlight!
I also agree with the consensus that Pearl Jam are a bit lame aswell. Sheesh! I don't listen to Nirvana really anymore but when I did I was recommended Pearl Jam and thought it was Christian rock. Well, not that bland but lots of boring song writing, blues solos and awfully nasal vocals.
