I really think that this lis all being over thought.
Lets put it this way, you are grateful that you have got positive feedback from a WG, Some can't be assed.
If you were her, describing someone as a Gentleman, is an easy term, that conjours up an image, always positive.
And saves her time in thinking of more accurate appropriate adjective e, its an easy simple description, which is unlikely to put off any other girls from seeing you, and thats the purpose of the feedback, is it not?
If you interpret that as being boring and plain, then thats your vision, probably not hers!
BTW I have some "Gentleman" description, but one added Kinky, now I think that is in my opinion a good description of me, and one i am more than happy with!