Have you ever tried to do those sports with cheapest equipment? Because I did and it ended up the same as everyone else who tried it in a cheapest possible way - you stop because it is not fun nor pleasure and equipment limits you.
That being said, for tenista you need to pay entry. For climbing, you will be kicked out of gym on top of it being uncomfortable. Climbing gym don't want you injured due to badly made seat - it makes other guests feeling bad.
That’s the thing about the discussion in this thread, and generally on HN. People just don’t consider that virtually without exception the realities of life, the choices we make, and the choices we can make, all form and are part of systems. Life isn’t a set of unrelated logic exercises.
That being said, for tenista you need to pay entry. For climbing, you will be kicked out of gym on top of it being uncomfortable. Climbing gym don't want you injured due to badly made seat - it makes other guests feeling bad.