I'd prefer it if the writer of the shell or make didn't make too many assumptions about my assumptions.

Even bash lets you escape unusual filenames for when you need them. Make will always explode your strings, and doesn't even attempt to let you escape them. I don't think it's unreasonable to expect a time-tested Unix tool dealing with files to actually handle all possible files.

So in order to deal with the real world possibility of spaces in filenames you choose to ditch a real world, useful tool?

Perfectly reasonable if spaces in filenames are a hard req.

In lots of scenarios they are not, and I prefer to assume that filenames have no spaces, and stick to make.