Everything sells off this time of year. Nasdaq is down 7% on the month. It’s end of year profit-taking for tax purposes. As BTC has become completely mainstream now, this makes sense.
No, it is almost certainly related to the network split, as mentioned in the article. There are issues with bitcoin that limit its long term potential. For example, the effective limitations on the number of transactions per second, and the huge energy cost for providing proof of work.
Please explain how turbulence in BCH affects Bitcoin and Ethereum.
BCH is a totally different coin, on a different blockchain, with a far smaller market cap than the "big boys" BTC or ETH. Its a poor explanation at best. Its the only thing that correlates to the drop, but it doesn't make sense as an explanation.