I think the point here is that i4i wanted to keep using it, but couldn't because Microsoft took everything they had and built it into Word for free. They destroyed i4i's business model (which happens sometimes) by stealing their design (which isn't legal.)

A business model based on setting a toll gate in front of an imposed monopoly is a business model that ought not to exist.

Well now, I haven't read the details of the suit, or their product, but it sounds like the plaintiff is selling an extension to Word - not unlike many companies (and myself) sell extensions to, say, Photoshop; or fibreglass spoilers for Hondas. Microsoft has frequently been caught red handed stealing other companies' ideas and converting them into Microsoft products. When a product has enough market share to become the market leader, and beyond that into monopoly status (Windows, Office, and Photoshop are ideal examples) then the owner of that monopoly only needs to fart in order to asphyxiate thousands. To roll over in bed might be a genocide. In the monopoly context, otherwise-harmless misdemeanors become positively harmful: For example, Adobe's passive-aggressive support for third party developers. In the continual drive to force upgrades and meet quarterly targets (etc), where the corporate well of originality - always rather shallow - has run dry, where else would you take your inspiration but from third parties? Anyway, I think "ought not to exist" is a bit strong, as the market for extensions would seem to be very helpful to consumers. It's just inherently dangerous to be a flea on a giant's ass.