MacOS was designed to run on a rather small range of hardware, although it was opening up in 1988. If licensed like DOS, it would have every bit as many compatibility problems.
Moreover, in 1988 it took some pretty upscale hardware to run it properly. (Anybody remember the Epson QX-10, a little earlier, which had essentially a Mac-type UI with a lot less horsepower? I didn't think so.) It also didn't run a great many applications. What we'd be looking at is something like the Tandy 2000, which was a more powerful version of the IBM PC with a color display that didn't hurt my eyes. It wasn't actually PC-compatible, but Tandy got a lot of software vendors to write versions for it. It was pushed in Radio Shack computer stores all over the country. Considering what happened to it, I just don't see Apple doing a whole lot better.