Absolutely, definitely not. There is no greater advantage in a football match, than a goal. If you have a goal and the other team doesn't, you definitely win the match. If you get a penalty you might or might not score. And if you don't, there's absolutely no guarantee that playing against ten men will win you the match. We're not there to second-guess the chances of a team going on to win a match with the other team down to ten men.
There have been loads of games where the team with ten men has performed heroically and either held on without conceding or even gone on to win the game. It's actually quite surprising how often it happens.
Goals are the most precious commodity in football and they're relatively rare - how many 0-0 or 1-0 games do we see every year? You should never chalk off an actual goal for a team on the basis that they might potentially then go on to score more goals afterwards. It's only if you've actually blown the whistle before the goal is scored that you can and must disallow it.
For instance, if you remember the 2006 UCL final, even the referee admitted he should have played the advantage and not sent off the Arsenal keeper. As the Grauniad report put it:
Also, in that match don't forget Arsenal actually took the lead despite being down to ten men - which shows that playing against ten men is not necessarily the advantage you might expect it to be (although Barcelona did eventually win the match, of course).