OR,t could be that MANY guys in their 40's and 50's have completely let themselves go and expect some kind of pity fuck.
Face facts kids,most middle aged guys are lard asses.People like looking at good looking guys.Fact is, most guys aint that good looking in their 40's and 50's..Sure,give em 20 years, the pushy ,have it their way guys will be lard asses too.But so what? Twenty years ago, when you were in you're prime, didn't you think you had it going on? I know I did,and never had a probelm getting laid.Guess what? I never did fat old men either.Why should I? There were plenty of hot young guys to do.
Cut the ''shallow'' young guys some slack.Most of them are no more or less shallow than you were 20 years ago.In the meantime and between time,if you dodge the raindrops,you can meet some really cool younger guys..
I know that sounds good and all...But really.
Say you're at the club, looking to get your dick wet.Suppose you're 63 ,fat, bald, drunk BUT confident when you stagger up to the cute 25 year old..At the same time,an equally hammered,perhaps arrogant,BUT gorgeous 24 year old guy catches ''your'' guys eye .Who's fucking who?
Chances are,while the ''arrogant'' guy is getting his balls licked later that night, the ''confident'' guy will be still waiting on a cab to take him back to his hotel room. ALONE...
I agree with Knucklehead. And would like to offer my opinion on on why younger guys are considered more attractive by a lot of people than older guys.
People like good looking guys. And good looking guys generally have a youthful look. Of course good looking is entirely subjective. But that youthful look appeals to the most guys. We see it everywhere. Pop culture, media, billboards, etc... It is marketed everywhere. The hot girls generally doesn't get the guy in the guy who looks old enough to be her father. You don't see guys with wrinkles in commercials for beauty products. And if you do, its generally to fix something like wrinkles or baldness. You especially don't see this online with a lot of people saying in their profiles 18-25 only. Does this attention we give to youthful beauty make some guys ( like the guys in the their youth) a little arrogant? Yep. But youth and beauty fades like everything else in this imperfect world. So let the guys enjoy it while they can.
But even though youth and beauty are attractive to most guys, its not just youthful people that get the most attention. Take a look at the straight community. Older women still get a lot of attention. The MILFs and Cougars are still considered attractive, even though young girls appeal to more men. But in the gay community the older men are generally not as well received as older women in the straight community.
Why?
In my opinion, from what I've seen, older women generally take care of the bodies. And when I say take care, I mean they go the extra mile. Manicures, Pedicures, Facials, (Not that kind) Spas, Anti-aging creams, skin rejuvenation, etc, all done in the name of trying to get the bodies to appear more youthful. Many of them continue to almost religiously shave. And shaving is generally equated with a youthful look. Which women do a lot. They even wax since in some ways, its better than shaving. Its a lot of effort, but the end result is them at 40 looking like their late 20s. Them at 50 looking years, perhaps decades younger. And straight guys of all ages appreciate that. Does it always work? No. But it works for a lot of them. People are attracted to that youthful look.
Older guys?
Like Knucklehead said above, a lot of them let themselves go, or they have a different definition of beauty. A lot of them from what I've seen are either chubby which seems to be the new word for fat in my opinion, got a beard, have lots of body hair, bald, wrinkles, a lot of them are proud their bodies look like jungles,

etc...

I'm not saying that's ugly. Everything is subjective when it comes to looks. But many people don't consider that attractive. And when it comes to sex, attractiveness is what counts the most, to most people. Even in relationships, attractiveness is a factor to a lot of people. It should not be the only factor, but how many people would enter into a relationship with someone they did not find attractive on any level? And how long would it last?
As knucklehead said above, an older guy who doesn't have a trace of that youthful look on him, who is fat, bald, has a lot of wrinkles, etc, will lose most of the time to the guy in his 20s. The older guy could be confident and the younger could be arrogant, a jerk, etc, but if they are at the club, guess what comes first?
In my case, I generally see women who are twice my age, and I am very attracted to them. I've seen one guy 10 years older than me that I thought was dead gorgeous. He could pass for his early 20s. Maybe he did a lot of stuff to make himself seem younger, maybe he was just blessed with good genes, who knows? But that's it. I've yet to see one man in his 40s that does absolutely anything for me.
So in conclusion, guys in their youth have a greater of chance of being confident to the point of cockiness, in part because of a general feeling of you can do anything/nothing can happen to you, and also in part of being considered attractive because of their looks which has everything to do with their youth. Are all young guys cocky? No. Anybody who can look youthful has a slightly bigger chance chance of being cocky. And cockiness is not just contained to that youthful look. Anyone of any age can be cocky.