I like to think of it like this -- before the PC we had CP/M and 8080/Z80 machines, and it was a fairly open if not fully standardized ecosystem. IBM muscled into that market and displaced it because they were close enough to those systems to not be too alien, but also sufficiently better to get people to switch and to attract new users. Plus their name and marketing advantages.

But in the end the market and community won out and pushed back into something fairly close to the original CP/M ecosystem, and we got the world of clones.