What does National Teacher's Day mean?

Today might be the first time I've ever really considered National Teacher's Day -- likely because I read about it on Twitter.

I wondered what it's all about. When I Googled it, I came to a National Education Association site. The news from the NEA was grim.

I was surprised, because I thought an NEA site about National Teacher's Day would be a place of hope. Then, I was faced with these statements, among others:

Teachers themselves are less positive today than in the past about the education and training they have received.

Forty-five percent of new teachers abandon the profession in their first five years. 

Teachers’ salaries still lag behind those for other occupations requiring a college degree, and the pay gap is growing larger.

I hate to be negative, but this day seems more like a bummer than a celebration.