I don't think the possibilty of qualifying next year adds that much more excitment to the final; the chance of winning the trophy/championship in itself is the true desire.
And of course, getting to the quarter finals, 2nd round can be a major achivement for a lot of teams, but you have to set the rule somewhere.
It would be another way of giving a losing finalist a chance to try again (more than likely they'll probably qualify via their league in any case).
It's almost mirrored in the way 2nd, 3rd, etc, placed teams (in their respective leagues) can now go into the biggest Euro competition (instead of just the first).
I just think it offers losing players a little more solace in the knowledge they'll definately be there to try again next time.
On the other hand; maybe neither should (as they propose for the next World Cup).