No, I don't feel guilty about using an ad-blocker. I feel annoyed for having to, certainly, because so many advertisers think they have a right to obstruct content or to interfere with content in such a way as to make the experience unrewarding and unpleasant. Not every advertiser does this and it is unfortunate that those that advertise responsibly are penalised so I do use my whitelist in some cases but...
Well, here's an example. A local news service near me fills their pages with adverts. These appear above, below, around and inside the news item to the extent that you sometimes wonder if they actually give a toss about the actual news. I blocked their ads which gave some semblance of normality only to start getting a third to a half page nag telling me to switch my ad-blocker off if I cared about the news.
The whole business of putting users that use ad-blockers on some sort of guilt trip is just the latest tool being used by irresponsible advertisers who only brought this situation on themselves.