Yup, I agree, I don't message anyone who think my age is 'too old' for them.
It does make me laugh ( and I say that sarcastically) at the amount of pot-bellied, comb over-sporting, beige-polyester-wearing, age 50-something men online who think I am 'too old' at 48, and say they are looking for someone 25-40. Snort, good luck with that then, mate 
I have been tempted to message the odd one or two in the past, just to point this out, but have restrained myself on the grounds that it would just
make me look bitter. So, no to contacting them.
As for profiles with no info: Annoying. I tend to assume they are too lazy to fill it in or have something to hide ( uber-cynical)
If i get a message from one of them, I reply asking why they have not filled in their profile and I politely point out that as I have a photo and info on mine, I'd really prefer to talk to someone who has the same. Sometimes they are just very new, and literally havent had time to put anything up. Other times they give some waffle about 'not liking to write about themselves' or they say 'ask me what you want to know'.
This grates on me, I feel like saying ' I AM asking you. I'm asking you why you haven't filled in your profile, you idiot. Why on earth do you think I have ANY incentive to ask an invisible man anything? There are plenty of men with photos and full profiles, what makes you think any woman is going to waste time messaging someone she can't see and knows nothing about? Put some effort in, man!' 