Sadly your very rational and valid points don't land for a lot of people as is apparent by popularity of such payment plans for just about anything and everything.
Someone making extreme statements like it is "absolutely bonkers" to lease a computer for three years are not necessarily "very rational and valid points." As I showed in previous posts, it can actually be financially better in the end to lease.
As far as people needing to be (more) responsible for their financial decisions and future, that is going to be true whether they pay cash, finance or lease but it doesn't mean any one of these is necessarily a bad choice or "bonkers."
Even for those easily able to pay cash, financing or leasing can be a smart move when the cash is earning more (after taxes) than the borrowing/leasing cost. "Strategic" debt/financing/leasing can be a good thing.
Sure, there are people who overborrow/lease, who are overleveraged, etc. just as there are people who overeat, drink too much, etc. but that doesn't automatically mean financing or leasing is "absolutely bonkers" anymore than going to a restaurant or bar. All of this can be bad in "excess" but it can also be good/positive or enjoyable when done right.