I really don't think you can say that Gates or MS made any breakthroughs in making computing ubiquitous. They were in business for a BASIC interpreter[1], created an empire based on monopoly and questionable ethics and frankly could not care less about the philosophy that paved the way for ubiquitous computing(that still is far from existing.)

If you want to give credit, give it to people who did the deeds to deserve it. People like Alan Kay, Doug Engelbart, Ivan Sutherland, Seymour Papert[2].

[1] http://programmersatwork.wordpress.com/bill-gates-1986/

[2] http://gagne.homedns.org/~tgagne/contrib/EarlyHistoryST.html