Most times I don't have to blame the casinos because most gamblers who go for this bonuses don't even have the patience to read the terms and conditions before going for it because if they do, then they would have understood that it wasn't going to be an easy task.
Nevertheless, I would prefer that the casinos make this terms very fair and not extremely against the player.
We can't blame the casino but must check what we've done to know what happened. If a gambler wants to get a bonus from an affiliate, they really have to be able to convince people that the casino is good and can be a place to gamble. However, people think that sharing affiliate links can bring them a lot of bonuses but that's not the case. They can get a lot of bonuses if people who join under them use big money to gamble so the bonus will also be big. But if they don't, they won't get a big bonus or even get anything.
Mind you, there are still many individuals who earn a decent income by sharing affiliate links. In fact, it's considered a safer way to make money in gambling because you don't have to gamble yourself to earn money. Instead, you simply need to persuade people to gamble and sign up using the link you provide.
It will be more successful if you have a YouTube channel or any social media platform where you can attract your followers to gamble.
There are people without doubt who are doing extremely well with referral bonuses and I'm very certain that those set of persons already have a very committed and active community of persons who trust them enough to follow their suggestions and so use their referral links.
In my few years of gambling and marketing, I've come to realize that mkat persons wouldn't want to use referral links of just a random person but rather would prefer to use links from top influencers and celebrity because there seems to be some sort of guaranty and I'm saying this from experience as referral hunter.
I'm not disputing your points but in affirmation to what you said but im.also glad you pointed out that one also needs some form of publication to be able to succeed and not just having YouTube and it's like but to also have a very active community on those channels.