I too was about to make the "why do you care what level I am" to the restricted ally invites. Then I got to thinking....
You can only count 5 allies per level, right?
So I'm guessing by the time you get to level XXX you have more allies than you can use in the levels around and below you, based on sheer percentages of players?
But your allies are always changing levels, so it can never hurt, it just might not help if you've got 74 allies on that level already?
Having too many allies may not be as bad as not having enough, but it is still a problem. You get "upgraded" to the target list of heavier hitters. I'm learning to check the rival lists for these "fast burners", some of them are easier pickings than the guys alongside or below my ally level.