I think that age limit is understandable
Ok, for someone who's in early twenties, age limits are understandable? Of course, you can apply whilst older folks can't! Less competition.
What makes someone, younger than me, better for the job?
Is it the fact of working for over 10 years with different kind of people, the fact of not being so impulsive on my decisions, the fact of being much more mature and thus creating a strong and good working environment around me, the fact that after having a well succeeded career I do know what I want for myself, the fact of being much more responsible and not going out at nights as used to be when I was mid 20's, etc, etc...
It is unfair (just so unfair) to not include someone in a job offer because of age and it is not understandable at all.