You should say "I used PHP because I wanted to use something I knew completely, rather than learning something new with unknown properties wrt fault tolerance." "I used Java 1.7 because Java 1.8 wasn't around at the time for the platform we're targetting."

If you can't come up with answers like that on the fly, you have bad "people skills" and are fucked. Interviewers doesn't care what technology choices you made, they just want to see that you'll fit into whatever little herd of programmers they are managing.