13, you make an excellent point.
That point leads me to this thought.
If we don't treat some of them like the kittens the pretend to be, if we don't take those and then get them to procreate in the hopes of making more kittenish snakes, if no one takes that chance of dying to tame and keep tame large snakes, then there is virtually no hope of there ever actually being large snakes as tame as kittens.
However, if some do take that chance, if they do go through tens or hundreds or maybe even thousands of individuals looking for "just the right one" to plug into a breeding project, and one of the goals of that project is to have kitten tame snakes, then eventually, someday, there is a very good possibility that that is exactly what will be produced.
Comparing apples to oranges here, if you can breed a dog to be aggressive, if you can breed it to have bug eyes and a curly tail, and do that successfully through successive generations, then it may well be possible to breed attitude into snakes.
I think it is well under way even now.