Lots of things are harder in space; maybe even everything. But it has some benefits, like abundant solar power, lots of room, and line-of-sight to large chunks of Earth.

Almost all the problems can be solved by cheaper access to space, whereas the benefits cannot be easily recreated on Earth.

Is it guaranteed to work? My point is that we don't know, despite confident assertions one way or the other. If it does work, the benefits are clear, and that's why it's worth trying.