Does the widespread sentiment shown on this thread to not fly on Boeing aircraft not give an incentive?
Only if translated into action.
Pro-active action would require not only advance knowledge of the aircraft that will be used, but also an alternative.
In every case that I have ever booked an airline flight the equipment is identified. It does sometimes change after booking, but for the most part you know what you will be flying on. And I know a lot of people who avoid specific aircraft types for a variety of reasons. The most common are perceived safety issues and comfort issues.
Of course there isn't always an alternative. Even when there is it sometimes involves more stops, longer layovers or less appealing travel times. But it is a real way to vote with your feet that a given aircraft or brand is not safe enough.
The downside to this "incentive" is that the public perception of safety has almost no relation to reality. Whether it is COVID, lightning strikes, being attacked by wild animals,, bitten by sharks, being involved in car crashes or being involved in airplane incidents the public perception of the actual risk is usually off by several orders of magnitude. Closing a loop with a really bad metric is seldom a good idea.