My question here would be: "Are we trying to build the best WordPress we can, or are we more concerned with powering 38% of the web?"

Not all hosts provide updates to php (or MySQL - mine doesn't, I'll be leaving them at the end of the year) but I don't think WordPress should be in the business of supporting hosts who haven't updated for the last seven years because they don't care. I guess I agree with Folmer; we should be driving on.