Because it's arguably not only sexist and class discriminatory but maids are no longer common in modern (https://www.quora.com/Other-than-series-whose-stars-are-now-dead-which-television-series-are-least-likely-to-be-revived) society.

Hazel wouldn’t work today because it’s not trash.

I love that show and remember watching it as a kid. Shirley Booth was such a good actress and I enjoyed her sparring with Don DeFore’s character. I don’t think viewers would enjoy it now.....it doesn’t fit the times....but that’s their loss.

It would work today if not only George and Dorothy BOTH had to work full time and needed Hazel to be Harold's caregiver, but ALSO if Hazel needed the job to keep PAYING those student loans from decades ago! Now whether Hazel would be in any kind of uniform outside the most formal settings is another question!