I think they are pretty much the same thing - men with guitars and a boner.
What is different from both blues and blue rock is the rape fantasy domination crap that some second wave metal artists came out with. (I'm not going to get into hip hop because I know bugger all about it).
I love blues rock and the odd squeezed lemon bothers me not too much.
I view all this in the same way as the lewder English folk songs that are not exactly free of boldily fluids. 'Bonnie Black Hare' is just a wee bit subtler than 'The Hunter'. Same basic deal though.
You'd have to ask a lot more women (and men for that matter) to ascertain whether one mode is inherently more offensive than the other to them. I would expect you'd get twenty differnt answers from twenty different people.