I like the small bottles and always take the partly-used ones home and use them at the gym. Same with the soap. (Yes, I AM frugal- more $$$ for travel.) And, if I'm in a road trip with multiple hotel stays, I may re-use the shampoo from a previous stay rather than open another.
Over 10 years ago I stayed in a hotel in Zurich that had a single dispenser in the shower, which was supposedly body wash AND shampoo. I was a little skeptical that it would do both jobs well, but supported the idea of getting rid of all the plastic mini-bottles.