No, you're not alone. I was brought up to think that salary-dropping and similar was vulgar, and potentially crass (as in, rubbing the nose of someone less fortunate in it). I remember asking my mum, in all innocence, and at the age of about 9 or 10, so no ulterior motive involved, how much my dad earned and her reaction was one of appalled shock ...... because, apparantly "you don't ask that sort of thing".
Okay ..... I think she over-reacted to a (her own) child, but I admit I still feel uncomfortable when other people state how much they earn. I can sort of understand it, in certain contexts, and amongst very close friends ..... but when there is a large group of you round the table, or when you're on an anonymous forum, where, chances are there are people from all walks of life reading any particular thread, I can't help but feel it's boasting, and it always leaves an unpleasant taste in the mouth (for me, anyway).
What I've noticed (and fallen foul of myself) though on MN is that when anyone suggests they find this vulgar, that a whole heap of others will throw the "jealousy" card at you and it's often very hard to explain that it's not someone else's good fortune you object to per se (that would be very sour grapes), but the way in which news of that good fortune has been presented. No-one would object to a poster who announced they or their other half had just had a great payrise for example, which would make a significant difference to their life ...... but if someone came along and announced, for example (and this is off the top of my head and I have no idea if this scenario has ever happened on MN, but similar insensitivity definitely has) that they had just got a £25K payrise I'd feel very pissed off at their tactlessness, given that a) many struggle by on less than that as a complete annual wage, never mind a payrise, and b)such a large payrise would indicate they were already doing rather well.