The cancellation of Segwit2x is a fantastic move made by the Segwit devs. They have finally realized that, right now, Bitcoin is not facing many scalability issues and the ones which it faces are resolved- which means that there is no need for the fork!
Bitcoin Core developers never had anything to do with Segwit2x. It was an agreement made by a bunch of Bitcoin service companies and miners. As such, the developers played no part in "cancelling" the agreement. That was done by a handful of the most influential companies.
But you're right that the scalability issues that Segwit2x was supposed to solve were blown out of proportion. I believe the congestion we are currently seeing on the network is partly due to concerted spam attacks by Bitmain. I'm not too concerned about it. It's annoying, but it forces us to use more efficiency in batching payments and avoiding unnecessary transactions.
The Eth parity issues are due to another network hack, but luckily it is not effecting many people- or the price as it has been steadily gaining the past few days.
It was not a "network hack" but rather a badly written wallet contract. In other words, it has nothing to do with the network/protocol, just one feature of one wallet. It sucks for those who have their ETH frozen. From a supply/demand perspective, it's actually good for ETH holders, though.