I'm a bit of a grammar snob. I'll admit it. However, I do believe that if you have a degree in education and are teaching children, you should be required to show that you have basic grammar knowledge and that you can apply said knowledge. You should be held to a higher standard than the average Joe or Jane. You should be leading by example. Our future generation is learning from you, and they are learning by listening to what you say.
I don't expect perfection (okay, I do), but how can you be an effective teacher if you can't speak or write properly? It amazes me how many people graduate college with a 4-year degree—or higher—and yet, can't construct a proper sentence. What has education come to in this country? It's an embarrassment to see these graduates who can't speak or write as if they received a college education?
On a related grammar note, if you apply for a communications position and there are typos and grammatical errors in your cover letter and resume, you can pretty much plan on not getting an interview. Just saying.
*If any of my teacher friends or kids' teachers read this, please know that I'm not speaking of you specifically, but of teachers in general, as well as other professionals where good communication is essential.