poofers, a special brand of ghosters
tldr; poofing (which i consider a specific kind of ghosting while actively talking to a person about plot or other things after a starter has been posted) is extremely rude, and imo, most rpers aren't assholes who harass people and would understand if poofers just said "i changed my mind / interest."
being ghosted makes me sad; sometimes disappointed when it's a plot that's been developed and i've become invested in. although, honestly, a large portion of my "ghosted" threads probably wouldn't have been so if i wasn't afraid to bother people for replies after several weeks to months of nothing.
on theother hand, poofing in the middle of a conversation meant to work through things (plot, OOC/IC expectations, etc) makes me so agitated. i don't take it personally, because i'm not gonna be that asshole who follows people around into their dm's demanding answers -- but, i do think it's rude as all hell.
i've told partners before that i've changed my mind for various reasons. it was received fine, and we moved on. i've been told before that i wasn't what they were looking for, and i moved on. i didn't whine about it or make the situations bigger than they actually were, because not every person who reaches out to rp will be a good match or work out. being upfront saves a lot of time of waiting for answers or wondering if something is wrong with them or me either IRL or as a rper.
if you're an adult who has already demonstrated the capacity to tell me that we weren't "vibing" you can tell me that you changed your mind. it's not that hard, and most roleplayers will be fine with that kind of honesty. most roleplayers will be appreciative that you were courteous.
a person can't give you content (IC or OOC) you want if it's not communicated. and you can't honestly get upset at someone for not giving you what you want / expect if YOU don't even know how to go about things or don't express it if you DO know. someone you reached out to online cannot automatically read your mind just because you have similar interests.
the proportion of roleplayers, imo, who follow, harass, and curse at rpers for X, Y, or Z is a significantly smaller population than most people will cite as their reason for ghosting/poofing (whether this is a firsthand experience or just in fear of). saying "sorry, i haven't replied. i don't have the time for this anymore / i've lost my muse" or a short "sorry, i changed my mind" is difficult, but if more people followed this courtesy i think less people would be afraid of the aggressive rper because they'd get to see that most people don't take it personally.
and i've seen and interacted with quite a few rpers who have been left questioning their own skills as an rper IC and OOC because their partners straight up left without a word or reason as to why the rp didn't work out. no specific reason for dropping an rp is owed ofc, but i do think polite honesty goes a very long way for a hobby that's supposed to be fun and tends to be community-based.