[userbinator]

One factor that hasn't been mentioned is that even the newest versions of the 737 contain ancient, obsolete technology

You mean technology like... wings? ;-)

More seriously, the "ancient" stuff is such because its reliability has been proven over decades of refinement. "Don't fix what ain't broke," as the saying goes. The aerospace industry moves slowly for a reason. I'd much rather fly on an old maintained plane than the very newest.