Why is every technology being declared Dead?

Declaring something dead is just the most readily available form of criticizing. Being critcal makes you appear competent without too much effort. And if you cannot follow the critizing person's judgement he/she can still look down on you and pretend to have just higher standards. It's a well-known trick in the corp world, and I have seen it described in books as well. That's why doers are weak in bigger companies, because most things you do are easily attackable, in their early feeble stages. And you just deliver something others can be critical to boost themselves.

Without having read any of the "x is dead" articles in question, I assume it's just a snowclone title used to draw in readers. "dead" simply means "less alive than (it used to be/some people think it is/it ought to be if it wants to grow stronger)".

Some of these articles will probably be worth reading, others will just be publicity grabbers. But that's orthogonal to the title.

It is an overstatement designed to attract attention at the expense of more considered and truthful statements. Like other forms of lying it should be discouraged.

Nothing is dying. Its just becoming easier to use the right tool for the job and coordinate lots of different systems, making any one tool easy to get rid of if it doesn't suit.