every casino that is offering a deposit bonus is scamming you
stay away from that crap
First thing, this is a good method for people to attract people coming to their site so I do not think that it is really that bad. The second thing, you are wrong on this because they do not scam you guys, for example they just manipulate some ToS that will confuse you so by some little mistake they will somehow confiscated your money
It is also not changing terms and conditions but their wagering requirements will be quite high and most of the users will lose their deposit before meeting those requirements. If you choose to play on a trusted sites then they will not cheat you. All these bonus terms we should read carefully before depositing money.