Agreed.
As people’s income and circumstances can vary so much, what is a lot to one person is pocket change to another. Therefore I don’t think anyone should be telling someone else “it’s only $100 you can afford it” when they don’t know that persons situation. People seem to assume if you’re going in a cruise you are wealthy, but some people will have saved for years to go on one cruise and it may be the only time they get to do it.
Therefore IMO the best advice is - it’s discretionary, auto tips will be added to your account, if you are comfortable
paying more and think the service received warrants it, then pay what you are comfortable paying.