Because I stay at a Hyatt in Hawaii about 3 times a year and I don't need piles of them. I also have absolutely no use for them. At home I drink out of a glass. It's just more junk and clutter. It goes in the trash before I leave. I'm certainly not going to lug back a cheap hotel-branded water bottle halfway across the pacific with me.

So instead we fill them with thicker (more plastic) reusable water bottles?

I would really like to see numbers on how many of these things Hyatt goes through. There are two in every room for every stay; more than two in the suites (also, real bottled water in the suites -- at least the "fancy" ones)

They like to talk about how many disposable water bottles they save, but I'd guess they in terms of raw plastic they are going through more, not less, with this program.

Don't get me wrong, I like the bottles. They are great for the pool or beach -- way more convenient than a regular disposable water bottle (mostly because you can put ice in them if you want). But I'm not going to lie to myself and pretend that it's doing anything at all for the environment. On my stays alone, they go through about 6 of these things per year. And that's for a total of, maybe, 7 or 8 nights in one room. My stays are definitely shorter than average, but the average stay is still probably under a week. They are probably churning through 100-150 of them per year per room. I'm sure that disposable water bottles would be better for the environment.