Comment 8 for bug 1522422

You are just repeating the same story that I've heard with every minor version. I still hear some broken obsolete code requires PHP 5.3. The major version bump is not as severe as with python2->python3, so there's a need to put a stake into the ground somewhere.

Also "think" is different from putting your money where you mouth is. Maintaining several versions of PHP requires a substantial amount of work. And the amount of work and support required is much higher when you release multiple versions of PHP as part of stable release than let's say supporting those versions in outside repositories (like my ppa:ondrej/php*).

Ultimately this would be a Canonical people's decision, but I strongly advice against having a multiple versions of PHPs as part of stable Ubuntu release.