> PC is the last major open platform.

In the whole history of computing PC is the only platform where buying a computer means crazy number of options and configuration mixes to choose from and expect it to work! And warranty would support it too! You can run any OS of your choice on it and that's also reasonable expectation.

Any other platform (SUN, Be, Amiga, NeXT, Apple) it was always buying it from one company only from its list of products. And even running with a different version of OS means warranty doesn't cover it.