Musicians - specifically, touring big bands - would sometimes make one-night hotel stops. Often they did this every other night to shower, wash a few clothes and catch up on sleep, which otherwise was had on overnight runs on the band bus.
Businessmen in various non-sales positions also found themselves traveling occasionally, say an engineer assigned to a field project, or a visiting muckey muck from the home office.
Many towns had hotels along a major highway or near the railroad station. They would cater to railroad men, teamsters, etc. Many towns would have one upscale hotel catering to businessmen and wealthier travellers.
In smaller towns, the hotel was often the center of a lot of social life, since it often had the best restaurant in town, and the bar might have a dance floor.
I agree that most ‘hotels’ here are pubs. Not all though. There are still a few hotels that are principally providers of accommodation. There are your upmarket Hiltons and such, and your fleabag transient joints, and the full spectrum in between. In my experience, all your non-pub hotels are in the big cities.
I stayed in this joint in Melbourne last summer. Middle of the road, old style city hotel. Had a bar/restaurant but the main game was the accommodation side of things. Note: anyone thinking of living there permanently should get a room away from the street (it was somewhat noisy at night). 
Another thing you will see in the US, is that hotels are often built in groups, several cheaper hotels clustered around a more expensive hotel that has a restaurant and a bar.