I couldn't agree more! There is nothing cuter than a 6 week old kitten, but they don't stay that way very long, and they can be royal pains in the butt! I know - I have one here right now.
Nearly every cat I've ever had was a stray or feral,and ranged in age from 1 to 5 years old.
One great thing about strays is that they aren't frightened of everything, as cats who have been raised in the house often are. They also usually are pretty cool about having other cats around, as they often live in colonies outside and are used to them.
The only problem I've ever had with any of them was their obsession with food, but even that usually fades when they realize they won't starve anymore.
My feral cats were (and are) the best - never even jumped on a counter or table, and never beg for food when I'm eating. Not being raised in a house has it's benefits.
Little kittens get adopted from us very quickly, but many people know the charm of older cats - and don't want their houses wrecked and their legs climbed - and request adults.
And yes, they can live a long time - my last cat lived til he was 20!