Emulation is slower, sometimes much slower, than applications that run natively.

With some applications you notice the emulation more than others. The applications may not be as responsive when you first open them. For the person that bought the Intel-based Mac and is looking for that performance increase, the bigger bang will come from the native code.

Linux use doesn't go beyond file servers or print servers because the applications aren't there.

If you run Windows on a Mac, it's another copy for Microsoft. Better yet, it's on a competitor's hardware. It would be like Microsoft taking it to Apple's home field.

Glory is chiefly distributed by the emulation and the despair of men of the same craft struggling in vain to reach the perfection another has attained.

Adopt the practices of successful people if you desire to be successful yourself.