What are ‘solvable’ games, and is being solvable a bad thing?

While trying to keep vaguely up on both games discourse and terminology over long periods of time, I frequently find myself noticing terms enter common usage, get used a bunch, then fall out of favour again. I think this is partly because games discourse is cyclical, and partly because writing and talking about the same things a lot means that when a neater phrase for something complicated pops up, it gets assimilated quickly. Mostly, though, I think it’s because of my brain doing the thing where, say, you notice a yellow car on a walk and then see dozens of them. I was going to write a car make there but I don’t know any. Uh, (looks at monitor), Asus? Do Asus do cars? The 1994 Asus Gremlin. What a ride!