I used to wonder why people “convert” from one technology to another. For example, someone might convert from Windows to Linux and put a penguin sticker on their car. Or they might move from Java to Ruby and feel obligated to talk about how terrible Java is. They don’t add a new technology, they switch from one to the other. In the words of Stephen Sondheim, “Is it always or, and never and?”
Rivalries seem sillier to outsiders the more similar the two options are. And yet this makes sense. I’ve forgotten the psychological term for this, but it has a name: Similar things compete for space in your brain more than things that are dissimilar. For example, studying French can make it harder to spell English words. (Does literature have two t’s in French and one in English or is it the other way around?) But studying Chinese doesn’t impair English orthography.
It’s been said that academic politics are so vicious because the stakes are so small . Similarly, there are fierce technological loyalties because the differences with competing technologies are so small, small enough to cause confusion. My favorite example: I can’t keep straight which languages use
elseif, … in branching.
If you have to learn two similar technologies, it may be easier to devote yourself exclusively to one, then to the other, then use both and learn to keep them straight.
Related post: Ford-Chevy arguments in technology
 I first heard this attributed to Henry Kissinger, but there’s no agreement on who first said it. Several people have said similar things.