No, it's really not (communism that is, Soviet style or otherwise).
Whether one agrees or disagrees with the article, comparison to communism as critique to patent system receives positive points from people who don't understand what communism is (ie. anti- "free market"/capitalism/american/etc. does not equal communism), and even then only from those who oppose communism anyway - better not try to drag any left/right arguments into this.
Also, I'm sure that Microsoft would love to have state given monopoly over everything they do - but as for patents owned by other people and companies, well, I'm sure Microsoft would rather not see them have right for state given monopolies - what I mean is that in current situation MS probably is seeing the patent system good for them, but had they not started building their patent fortress in time they would most likely now be criticizing the patent system for stiffing competition.
And that's the exact reason why software patents are evil - they give all the power in software business to those big ones who have all the patents, and those who don't get pushed or bought from competing with the big ones.
As for being UnAmerican - that's a huge argument I'm not going to take a side to. I would feel mighty stupid for saying that something is UnFinnish to argue against something though... I don't think it's very good argument, but seems to me that it's powerful, if empty, way to get peoples attention is USA ;) But as I'm Finnish - and greatly against software patents - an argument about something being UnAmerican really means nothing to me...