"Why is it reasonable to believe in prisons, but not in the hell?"

[FlatAssembler]

Don't ask questions you don't want answers to.  

Seems more like a question you should be answering yourself.  We can take the assertions in your fallacious argument to be truly representative of how you feel about a matter even if they aren't representative of facts in mere reality.  

It would be bad if x, therefore x doesn't exist/doesn't happen.  You've employed this argument for massacres, and now prisons.  You're the one who declared it a shithole, if we're being introspective about it, aren't you?

Well, you are claiming prisons exist everywhere, not just in Croatia, right? Besides, there are reports about people getting into jail for mean tweets everywhere, not just in Croatia. If anything, you are less likely to get into jail for what you say in Croatia than, for example, in Germany. Mate Kapović, probably the most prominent Croatian linguist, is openly denying Bleiburg, and faces no consequences for that. In Germany, if you deny the Holocaust, you allegedly get years in jail.