Maybe I'm reading into it a bit, but I doubt the guy is so obtuse that he doesn't realize there's enough money to go around for the various forms of locomotion. I think this is just some defensive posturing he's doing in public to try and paint his company's products in a better light against the soon-to-be competition.
Here's what I see:
1) iRobot is a major supplier of defense and security robots currently in use by the US military.
2) iRobot's entire lineup is based on wheeled or treaded robots. There's no indications of them being anywhere close to fielding a walking robot of any sort.
3) Meanwhile, Boston Dynamics, a small company that wasn't yet a credible threat, has been working on both bipedal and quadrupedal robots for DARPA that are to the point where they're being field tested by the military.
4) Then, Google bought Boston Dynamics, meaning it suddenly has far more resources available to it than before, making them a much more credible threat.
5) And now, shortly thereafter, iRobot's CEO suddenly comes out trashing the technology used by the competition, just as that technology is reaching a point where it can start entering the market.
As I said, I might be reading into it a bit, but the timing and notions just seem weird. For instance, going back to the summary (emphasis mine):
The reason it has taken so long for the robotics industry to move forward is because people keep trying to make something that is cool but difficult to achieve, rather than trying to find solutions to actual human problems.
This is pretty clearly posturing on his part, since he has to be aware that none of his Roomba products can navigate stairs, an extremely basic and common component of building interiors. It's obvious that his products are not offering "solutions to actual human problems", or at least not to all of the problems, and he's scared that others will realize it too. It's good that he is, since his company isn't set up to deal with it, from what we know publicly.