Good teachers deserve our support. Not the bad ones. Being a teacher doesn't give you an aura of nobility simply because.
I don't quite agree. I think if someone goes into teaching with the desire to do good, accepting that they'll never get rich doing it, and it turns out after training up that they're just not very good at it, or don't like doing it, or maybe after 15 years are just plain tired of it, I think they still deserve our support. In this case support might mean radical counseling or retraining to either make them good again in the classroom or find them another niche where they can be productive.
I think we have to accept that not everyone's going to be able to stand 20+ years of dealing with some of the little shits and their insufferable parents, bureaucratic bullshit, false abuse charges (I have relatives who are teachers), etc. We should plan for this.
And yes, of all the professions, I think teaching is one of the most noble. It's just in a completely different class than going into, say, marketing.