But if you think that the whole idea is fine, then go for it, or if you think it's evil on the other hand then that's OK as well.
But you must seriously make up your mind before you start, because trying to generate income from blogging is difficult enough without second thoughts kicking in and making your attempt half-hearted.
You should feel good about earning income from your blog, there really is nothing wrong with having an urge to succeed.
If you honestly think that your blog has real value, then you should be earning income from it.
But you can't be shy about the whole thing, if you're going to put up ads, really put up those ads it's the same with requesting donations, you can't be too obvious with these things.
There are always some who will complain when you commercialise a free site, they always do.
But is it possible to make a proper living online? Undoubtedly, although if you have a day job it could take a little longer but the opportunity exists.