The people who use fake QR codes may have the following reasons.
In order of most plausible:
1: the virus doesn’t exist and I just want to be able to party.
2: I’m not going to inject anything into my body that hasn’t been tested enough and no one takes responsibility. I also don’t get that sick if I get Corona, because I’m young enough.
3: I have been vaccinated 2 x (Got through Corona), but the system doesn’t show that and I can’t take an extra shot.
Only for the 3rd group I can imagine doing it like this. That the system sometimes fails and despite the 2nd shot does not enter the system is just ridiculous.
As far as I’m concerned, Group 2 would therefore not be able to participate fully and should take it easy for a while.
Having said that, I think it’s rude that you can go to the cinema, terrace and gym for a long time and that you suddenly have to be able to show your QR code. This is also in locations where little or no infections have been reported.