It does appear that we could buy the game if we wanted to.
It's not unusual for people to view a game and:
- not download the demo
- not to buy the game.
I doubt it has anything to do with the game itself.
Rather it's probably the target market that views games on itch.io.
It's why you'll notice so many threads here about marketing games - and marketing them elsewhere to drive the traffic here.
(For example, before I deleted my devlogs, one of them had about 250 views without a single click-through to the game page, or anyone downloading the free demo.)