Other than DirectTivo, sales of the two were reasonably close. Tivo NEVER made money, but Replay was profitable, which is why it survived. And lawsuits started at the very beginning, with Replay and Tivo ending theirs as not in their best interests. When SB was sued for CS they made it manual instead of automatic.
You can promote any theory you want to invent, but the SB CEO has stated many times that lawsuits had no effect. Any time you over-pay to buy a business selling millions (RIO) that overnight goes to zero, you're going to have a problem. And SB did it with more than just that 1 product line.