When I'm passing on a MUP I'll call out "passing" to warn the rider , walker, or runner I'm passing. If they acknowledge they have heard me in some way, the experienced simply raise a hand. Then as I pass, I will usually say "have a nice day" and usually get a "You too" back. If they don't acknowledge my call to passing, I pass without any further words. This isn't to be in anyway passive aggressive towards them, rather some people are just in a zone and I don't feel like intruding. I've warned them that I'm passing, if they don't hear me or care, there's nothing I can do.
I usually don't say anything on the road when passing unless I'm passing relatively slowly where it almost seems like you're riding beside them for a short bit. I don't need to call out passing as I'll swing out from the shoulder to the traffic lane and there's no safety issue.
I also generally give a wave to oncoming cyclist or others like runners and walkers. 80% of the time I get some wave back. I won't do this on a busy MUP as I'd be waving so much it would be like I was in a parade. I don't sweat the ones that don't wave back. I know that sometimes while riding, my head is somewhere else or I'm just concentrating on a road hazard and I won't notice a rider on the other side of the road in time to wave back at them. So, I don't take it personally if a rider doesn't wave back to me. And of course riders on TT bikes, I don't expect that at all. Though some will raise their fingers to "wave" back.
I would never get upset with anyone who ignored me, let alone give them an F-you. I have no right to expect any interaction from other road or MUP users beyond what's needed to do things safely.