It's so weird the herd behavior of developers.

I would expect that's true in any field that moves as fast as software development.

Developer A makes a move, perceives some benefit, tells developer B, who does the same thing and then tells developer C.

Some of the people consider the move, weigh costs, and make an intelligent decision. Many just think "smart people are doing this, I'll do it too". I really doubt this behavior is unique to developers.