Sorry Urco, but your logic is flawed. Would you like coffee or cake is the correct question. If no, then present check. If yes, the find out if just coffee, just cake, or both. Fastest way to eliminate those who want neither, while presenting the option for 1, both, or neither.

It's more like 80%. That means roughly 1 in 5 dev projects is NOT using php, linux, etc. That an awful lot of developers you are discounting as worthless simply because they work in the minority. I've been doing this for a long time, there is a huge difference between a dev that doesn't know how to do something simply because they haven't worked on it, yet, and a dev that thinks whatever they know is the only thing worth knowing.

@SpencerBeige nice pun!

Not every backend is on Linux, not every source repository is in Git. Teach people how to use the tools your team uses. You had to learn once.