Summer school isn't required. You can't get fired for not working summer school. A district could be unreasonable and not renew a teacher without tenure/professional status for not doing it, but right now, they're in no such position.

PD isn't required. Prepping isn't required. And when the first day of school hits, teachers are judged on their ability to teach. Protesting in the summer to an audience of no one and calling bad lessons later on the summer's protest makes no sense.

>I quite literally proposed an alternative way to bring about contract agreement.

So did I. Tell districts to be proactive. If not, teachers can be "retroactive" and protest after a long period without changes. Seems to work. Make it so this kind of protest can't work and you'll be in good shape. No one wants to have to protest, but we don't live in that kind of world.