This might seem kind of ridiculous, because Hudson (who will turn 37 this year) only has 181 wins and has never won a Cy Young award. His win-loss% (.651) is excellent, but overall he just doesn't seem like Hall of Fame material. At least some part of that calculation, though, is rooted in the idea that a starting pitcher (unless they're Sandy Koufax) needs 300 wins (or get really close) to make it in.
Look at Bert Blyleven: he finished with 287 wins and was superior in many ways to pitchers already in the Hall of Fame with 300 wins (like Phil Niekro), but it took him 15 years to be elected. For the time being (it will change with Maddux, Glavine and Randy Johnson), Blyleven is the only starting pitcher (I'll exclude pitchers like Eckersley and Smoltz who had unique careers combining starting and relieving) to start his career after 1967 and make it to the Hall. There are various reasons for this, and one is the sustained reliance on 300 wins as a necessity.
Tim Hudson is just an example of someone that should be looked at. It is common for voters to the Hall of Fame to evaluate players against other players from their era, not just some never-changing benchmark. Tim Hudson has been one of the best pitchers of the past decade.
Since his first year in 1999, he is 2nd in wins (to Roy Halladay) and is 7th (!) in W-L% of all pitchers with 275+ decisions since 1900 (Whitey Ford, Pedro Martinez, Lefty Grove, Roy Halladay, Christy Mathewson, Roy Halladay). Are these Hall of Fame credentials? Probably not, with the current way of voting.
Winning 180 games over 13 years wouldn't have been that amazing if you starting your career in 1965, but times have changed. The emergence of 5 man rotations and heavily used bullpens cut into the number of decisions every pitcher gets, even if they stay healthy.
It is true that Johnson, Maddux and Glavine managed to win 300 games in the 90's and 00's, but that is becoming increasingly rare. It might be time to rethink what it takes for a starting pitcher to get into the Hall of Fame to match the way the game is played now.