Thing is, though, it being understandable from a business standpoint doesn't make it okay. Their claims were groundless and everybody knew it, yet they tried to intimidate legitimate competitors into backing down with the threat of legal action. That's some SCO shit right there. A good business responds to competition with counter-competition, not by trying to bully their competitors out of the market.
It worked for Microsoft, and look where it got them, so it is no wonder that others try to use those tactics to defeat their competition, instead of just making a better product at a competitive price.