Like I commented in the issue, it doesn't matter what the maximum PHP version is, because any hard version limit is arbitrary, and any hard version limit is wrong. This point didn't seem to have reached the intended audience, and was largely ignored. Even Rarst, when he raised the same point, was told:

Given PHP's poor adoption curves, all that this means is that you can't release a plugin through WordPress.org that only works on 15% of WordPress sites.

This is a non-answer, because the choice of platform, even a poor one, cannot come from anyone but the developers of the products themselves. Even more so, given that WP runs on PHP versions that are higher than the current arbitrarily set minimum.

The only acceptable solution is to make this check optional, like I write here.

This is outrageous.