My comment about "building things cleanly" is more about making a clean break from the past. It's not in their DNA, and since Windows 11 is doing that, I expect they'll hit some bumps in the road.

As for being a "one-off" issue was whether the bugs resulting from the clean break process are just a few, or if there is a whole host of issues that are about to crop up due to the big changes that have been made.

Windows 11 is technically simpler than 10[0], (not sure what the LOC counts are like though), but when changing/removing a bunch of things, I expect they will have issues. It's hard to do when your history is adding things for new features and keeping old code for compatibility - different process & different thinking.

[0] - I'm ignoring WSL here as a whole because I'm not familiar with the architecture yet.