It doesn't sound like they are trying to profit off of Microsoft's design. They're reacting to the reality that Microsoft has a near monopoly in the word proces

It doesn't sound like they are trying to profit off of Microsoft's design. They're reacting to the reality that Microsoft has a near monopoly in the word processing market, and many users are much more familiar with that interface. It makes it easier to transition a new user if the interface feels familiar. If they were actually trying to profit from Microsoft's design, they wouldn't be providing a "Microsoft Word Mode" they would just make that their only interface. The idea is that they would be trying to avoid innovating themselves and would just be attempting to use Microsoft's interface design research to make a quick buck. You see how this is not about trying to cut corners in designing an interface, and more about user familiarity? (I'm being charitable here in assuming for the sake of argument that design is a legitimate thing to patent. I don't think that's the case)