I work at a medium-size hotel (~80 rooms), I can offer some insight. It's a combination of accessibility, cleaning, and maintenance. Accessibility: a hobbed sh

I work at a medium-size hotel (~80 rooms), I can offer some insight. It's a combination of accessibility, cleaning, and maintenance. Accessibility: a hobbed shower - the small ridge, step, plinth, etc., around the edge of the shower base, that keeps water in the shower - is quite simply a huge dealbreaker for guests with mobility issues. Tripping over a toe-height ledge and trying to regain your balance on wet tiles is dangerous. Most accessibility-friendly non-hob solutions are going to let water out of the shower and onto the rest of the bathroom floor somehow, which pushes you towards a single joined floor for the whole bathroom to avoid water damage. Cleaning: Complicated surfaces, little pokey panels, extra seals, moving parts. All of it means cleaning takes longer (cleaning is by far the main cost for a given booking), and it also means cleaning is done less thoroughly (leading to poor reviews on cleanliness due to accumulating mould, grime, etc). Shower curtains in particular are brutal on your review score: they are hard to clean, so the cleaners don't do a great job, so they get mouldy quickly, and your guests hate this and give poor reviews for it. Maintenance: The median guest is fine, but one in twenty guests is just a hurricane of destruction. Want a shower door? That means hinges, which will snap and drop the door when this guest slams the door open or shut. Want shower curtains? This guest will grab them like they're handles and tear down the curtain rod. They will twist off tap handles and somehow lose them, they will pull those shower mixer taps out of the wall trying to get more water pressure - just about anything you can think of, plus many things you can't. (If you don't have a "one joined floor" setup, you're relying on the shower door being closed to prevent water damage, and this guest will definitely shower with the door open.) In the end, the main reason hotels can't make showers easier is fairly prosaic: they have to make showers robust towards all sorts of guests.