Some see it as "settling".
As you get up in age, you start to realize that looks really aren't everything. Recall the classic:
Arm candy is great and a good lay with a freakshow is fun, but eventually you look for someone you can actually live with on a day-to-day basis; someone who actually enjoys sharing things with you besides just the bed. Sometimes the hottie is that person... more often though, it's things BESIDES the outside shell that you start to find attractive.
Like if you have a warped sense of humour, a decent-looking chick that will laugh at your stupid jokes AND give you more, WILL ACTUALLY BE MORE ATTRACTIVE to you than the hot blonde who just gives you a stupid look when you pull out your best knock-knocks.
Or if you're into, say, esoteric sci-fi, and you meet that chick who actually wants to cozy up and watch your Red Dwarf collection... even if she's what you would have considered mediocre-looking in your youth, you're likely to actually find her HOTTER over time than the bimbo who will turn off a Kryten monologue just to get you to bone her. (The one who'll bone you and THEN go put on the Red Dwarf, well... that's the Holy Grail!)
Keep in mind that some chicks age better than others. Thinking back to a recent 20-something-year high school reunion I went to... there were a few of the hotties from back then who still look amazing... quite a few who have aged fairly well... and several who fall into the "WTF happened to you???" category (see Jason's freaky chick above).
AND there were even more who were the nerdy, outcast, bookwormish type back then who've now become HUMMANAHUMMANA hotties that you go, "Holy shit, why wasn't I dating YOU in high school???"