Why is the 737 Max Such A Disaster?

I am going to try my best to fly Airbus only on domestic routes.

"Disaster" is a bit of an exaggeration at this point. What caused this incident is the fact that the 737 Max 9 has a few differences in design compared to other 737s.

The "door plug" is a feature of the Max 9 that is present in many other aircraft. The idea is, the fuselage is manfactured (by Boeing, in this case) with several configuration options for the eventual buying customer. One of those is to have an emergency exit door where that "door plug" is. However, it's only necessary to have that additional emergency exit door when the aircraft is configured for maximum passenger capacity, which it usually isn't, as things can get tight in there (Spirit, by the way, orders all its aircraft for maximum passenger capacity).

So you have a door-shaped cutout in the manufactured fuselage, whether or not the extra emergency door will be installed there. If it isn't, the cutout is still useful, as it can allow access for inspections and maintenance from outside the plane. In such a case, a "door plug" is installed.

The door plug is held in place with several bolts as well as several stop fittings. The bolts have to be properly torqued; otherwise, the stop fittings may begin to slip. If the failure to properly torque the bolts continues, the stop fitttings will continue to loosen. This will ultimately put too much stress on the bolts, which may fail.

So I interpret this as a failure to do proper maintenance rather than a design flaw. Planes with door plugs may be rare enough in Alaska's fleet that mechanics aren't familiar with the door plug bolt torquing process.

In short, rather than not flying on the 737 Max 9, I might not fly on Alaska.