Yes, gambling require the self-discipline to avoid addiction, when faced with tempting bonuses one needs to be careful and set aside a limit to what to do and how long to stay in the game even though there are lots of cash backs or bonuses. Most time, gamblers fine it hard to look away from good bonuses, and this has made it hard to avoid them.
it's hard for a gambler to be able to resist the temptation of a bonus or cashback offered by a gambling site, i see Coinplay also does promotions like that, and it's a natural thing to do as part of a marketing trick. what a gambler needs to do to keep from losing badly is to try to stay patient, not use emergency funds or even go into debt just to gamble.
If all casinos use bonuses and loyalty programs, it is not surprising that Coinplay.com uses them. Welcome bonuses are especially popular, because it is necessary to somehow attract players to the casino.