Could you explain why it's a bad trend? I've had crap laptops in the past that have struggled to run the desktop apps I need, and something like this would have really helped me out.
Personally, I'd prefer to pay up front for a machine that offers all this performance that I will own and can do whatever I'd like with for years instead of renting. I lean towards this for most things (housing is a bit different because of the size of the purchase). A computer isn't the kind of thing I wouldn't be sure of it's use to me, so I'd definitely pay up front, get better specs, and save money within a year.
If this didn't have the minimum hours of usage, the concept would be neat if you only spend 8 hours a week in some intensive software. That would be a great use IMO. I bet there are already a handful of those offerings though.
Things like this move more and more of our data and usage of computers into centralized hands. I'd suspect your typical HN user prefers to maintain control over that.
You can rent a paperspace or amazon vm with a high powered GPU if you want to play games from a cheap netbook. This is just that, except with less power and no control over the machine or OS you're using. In other words, overpriced and unsafe.
This would not really solve your "crap laptop" problem when it comes to cost. The service will cost you more than simply buying a really powerful laptop that will lead to much a better experience.