Why younger guys after older women ???

I havent dated in a long time and into internet dating and I am finding allot younger guys emailing me , and i plainly state that im not a sugar moma and looking only for friendship first then relationship ,, all i get is younger guys , how can a 30 y.o wont a 42 y.o women for derious realtionship ,, even got them at 2oish asking ,, can someone explain this