That's fair. I have no illusions about this: I know I won't convince everybody. When Diamond and Pearl are released here, I'll set up a a group of people who want to try battling without Hidden Power, Legendaries, or base 600 Pokémon. That way people can try it out to see if they like it. Besides, it's not like they have to use these rules exclusively. I'm sure it's fun to use Legendaries sometimes. Maybe this gen I'll broaden my horizons and give that a shot. It wouldn't be fair for me to ask everybody else to change if I didn't give their way a try.
As far as the counter-arguments being stronger, I think there are two questions we all have to ask ourselves. First, do you believe that removing Hidden Power and Legendaries would make the game more interesting by adding variety and encouraging new strategies? Second, do you want the game to be more interesting, even if it means learning a new way to play? If you answered no to the second question, then you and I can just agree to disagree and go our separate ways. If you answered no to the first question, why don't you try battling my way just to make sure you're not mistaken? Of course, if you answered yes to both questions, then you and I are in total agreement.
I see two basic camps on this: people who really love their tried-and-true metagame the way it is now and don't want change because it means they'll have to learn all over again, and people who want a bit more variety and strategy. I respect both viewpoints, but I can almost guarantee that those of you looking for more variety are better off playing without Hidden Power.
For those of you who think that Hidden Power and Legendaries make the game more interesting, why not try it my way? What have you got to lose? I'll certainly be trying it your way. I've been wrong before.