Apparently, the developer community wants to take a cautious approach and doesn't want to rush with the release.
https://coincodex.com/article/2730/ethereum-constantinople-upgrade-targeted-for-mid-january/
the mining reward from 3 to 2 ETH per block, with no price spike will be a big headache for regular mining community
The price is already so low that a 33% drop in mining reward isn't going to make anyone suddenly less happy. My small mining setup is officially in the red, thankfully it has paid for itself over the last couple years and I just have to worry about energy cost and occasional maintenance. I'll keep running to help secure the network but profitable it sure ain't right now.