Why female(s) don't like to be asked about their job?

I personally don't think there is anything wrong in asking a woman what her age is, if you are "tactful". After all, many women today do not look their age, some are younger and some are older, so, if you are a guy who is in his mid 40's, and you are interested in a woman, who looks like she's also around that same age, you may say "many women these days look alot younger than they really are, don't you agree?" Like my sister is very young looking for her age, and these days it's so hard to tell. The gal you're talking to may then tell you her age, and you'll find out without even asking. Or you can tell her what your age is in a casual way, and she may just tell you also. I can't see how you would not want to know how old someone is that you are interested in dating. As far as a woman's job goes, I wouldn't have a problem with someone asking me about my job. To me, it shows interest. But, possibly, the only reason I can think of it being wrong to ask, is because the woman may be suspicious of the guy's motives. I don't know, personally, I have never heard of that being a no-no.