You don't get to use your feelings like a weapon like that.
But it's OK for you to use
your feelings against
them as a weapon?
Look, if I have a close friend in my group and he's mauled by a tiger, there probably won't be tigers.
The fact that you said "probably" when it involves a "close friend" doesn't suggest that
you're a very good friend.
If some person in my group brings a random guy to the table, and we have long had tigers as part of the setting, I think it is fair for our group to decide whether we feel that is a reasonable thing we can accommodate. But my point is, that person doesn't have a right to impose a demand on the whole table because they have this feeling about tigers.
How important are tigers to the game that excising them would be disruptive? Now, if the entire
point of the game was tiger-hunting, then sure, changing the game would probably be too much. But if tigers are an incidental part of it? Like, they may show up as a random encounter table? Then how selfish do you have to be to be unwilling to change "tiger" to "giant lizard"? Hell, you could even use the same
stats and just describe it differently.
Doesn't mean we should make fun of the person. Doesn't mean we shouldn't take any distress they are feeling seriously. But it just means we have to be able to negotiate these things on a case by case basis. This is doubly the case if we are trying to run a Ravenloft game and someone has a request like 'no ghosts' or no 'possession'. I can sympathize with their feelings but also decide that removing that element would undermine the game too much,
That exact thing happened in my game! When we got a new player in the game, I asked him if there was anything he didn't want me to include because it upset him--
especially because I run a lot of Ravenloft. Due to his unfortunate religious upbringing, that thing was being possessed.
So guess what?
I don't include possession in my games. I can have ghosts and fiends that do things other than possess people--since you've read the two associated Van Richten Guides, you know how many options there are for them. I have probably hundreds of monsters that I can use (especially since I grab creatures from other editions, settings, and even from other systems), and I can use each monster in probably dozens of ways, and only a
single option has been taken away.
Nothing was undermined at all. I don't even have to do the "be more creative because I have limited options" thing, because I still have a zillion options to use.