The first doesn't take much room compared to what it does, it can do a lot of things decently, might cost more on the long run but is cheap to start with. I think someone needs to first feel limited by the all-in-one's printing capacity, performance or cost to fully understand what will the laser printer bring to the table.

And this works at any level. Photographs using zooms lens switch to single focus length lens when they hit a point they want more of X or Y. Otherwise there's no point in giving up the convenience of multi-purpose solutions.