If the entire organization is offshore then fine, but the time zone difference between they west coast and Europe is too big for close collaboration. South America is ok but there aren't many software developers there.

> but the time zone difference between they west coast and Europe is too big for close collaboration

This is definitely part of it, but if you have east coast or central teams, this is totally doable. In fact, often the European employees get more done as they get a whole morning before the US based pings/meetings start.