Anything above 30x is too high for me and I don’t think I could complete it before losing all my money. I wouldn’t claim any bonus with such a high wagering requirement.
However, if it’s free money (no deposit required) then I wouldn’t care about the wagering requirement no matter how high it is. If I complete it and make some profit then that would be nice, if not, then it doesn’t really matter as I've lost nothing and spent some fun time playing games for free.
Anything above 10X is already high for me

I understand the reason as to why casinos try to keep it as high as possible. It's business, and you don't want to pay off massive wins from bonuses or the casino could run dry. From the fun point of view, it's highly welcomed by most players.