Yeah, it's hard to feel sorry for people who come in and complain when they lose. I do agree, sometimes some people are predisposed to be more vulnerable to gambling, putting in more than they can afford to lose, but that's more on them and not on anyone else to watch out for.
Silver lining though, if the guy isn't coming back, then he's saved himself more misery from further losses. Always think of gambling as fun, guys.
Ultimately gamblers are very likely to keep playing & depositing so in the end the house will nearly always win in most cases, the most vulnerable people don't seem to realise that until it's too late and lesson learnt, it's definitely sad to see and I've done this myself in the past but gambling responsibly at the end of the day and comprehending you'll be able to lose that amount is key, stake also do actually do a good job giving back to users, more than most industry standard casino reward systems, +1!