Is it less impressive when rich guys win a big tournament?

Very less impressive. What's awesome is when Joe Shmoe wins it. Little-man handles the pressures of ALL THAT MONEY at his seat, how to wield it, not to be afraid of it, thinking of What If 's. Those kinds of things.
A rich man knows how to handle large sums of money, and has played at much higher stakes than the rest of the real world. Not so with Little Man.

It's like a bunch of us ordinary/not-rich people getting together and playing for pennies. "I am the winners of the $5 worth of pennies!" Big deal, you already had a bunch of pennies before this.
(of course there will always be those for whom $5 is alot of money too!)