I wouldn't be too quick to jump on whoever Joe is. When I was about 3 months new to the game, I went to an informal tournament that was won by somebody who had literally never played before that night. Granted, it's anecdotal and not nearly the level of play that happens at a national tournament, but there were multiple people there who knew the game well.
So, as much as I love Dominion, I also think there several key issues that prevent it from being a good tournament game. The biggest one is that there's enough luck to require somewhat large sample sizes before you can confidently determine relative skill; that's hard to do in a day / weekend. Obviously, the variance in starting 4/3 vs 5/2 on a given board is also huge.
A more subtle issue is that Jay (who I don't know and can't speak for) seems (based on hearsay / forum reports) to have what I would call a "casual gamer" mentality. It's disappointing to hear that he "really hates" 2-player, as I see a lot of value in it as a competitive format. Also, I get the impression that he's focused on a nebulous idea of "making it fun", which sounds really weird to say. Dominion should be fun, but people have fun in different ways. A community that cares about tournaments also cares about technicalities, rules decisions, and minimizing variance. That is part of the fun for competitors. I'd be really disheartened if I flew to a tournament and felt that the weekend amounted to "hey, let's hang out and play some Dominion." A tournament should be about determining skill because that's a lot of why competitive players even show up.
This is all from my limited perspective; I'd love to hear others. Again, I don't know Jay; I don't want to vilify him or accuse him of anything. But my impression is that the guy in charge of official Dominion tournaments is a pretty casual about it, and that makes me a little sad.