I don't know why I'm surprised, or even affected by it at all. They didn't talk to me for ages and then when I reached out they weren't interested - I really should know by now that always happens eventually.
To me, that's really fucking annoying, you did the decent thing and boof, not interested, sorry, I hear ya, I'd be really irritated by that! It may last a few moments or I dunno, but ummmmffff urrrrghhh annoying!
Friendships aren't easy, but maybe try not to take it too personally. People's lives and priorities can change over time, and sometimes friendships simply drift apart.