Hubert's exactly right here. We upgraded the license because GPL3 is better at protecting basic Freedom and because we could. We will never downgrade the license.
Software patents (and especially the US ones) are immoral and should not be getting mixed up in Moodle code. They just have potential to cause too much trouble for Moodle users. I will very happily live without code that is encumbered by such madness, and will not cry if if the legal parasites that feed on patents go out of business.