Perhaps they are indeed all hellholes. If so, I'm very glad I don't live anywhere in Chattanooga. I have never been there, and perhaps it would be idiotic for anyone to take them up on their offer.
But I admire them for trying. I'd like to see more American cities succeed in reviving their urban cores. In so many places in America you have to be a half-hour commute from downtown to live in a safe neighborhood with good schools... and that's just sad.
Most people in Chattanooga live in the burbs, so I feel like there may be skewed perspectives as to what counts as a nice place to live. Downtown can be quite nice by urban standards.
While it might not be the best place for technology in the universe, it's a very nice place to live, and I'm glad that they are incentivizing tech and making the most of their internet infrastructure. It does seem a bit gimmicky overall but the incentives might tilt it to being the best option for some talented people. Who knows.