1. Bunch of up-and-forget sites on shared hosts 2. A metric ton of legacy codebases that plain don't work on PHP > 5.5 3. PHP 7 had quite a few breaking

1. Bunch of up-and-forget sites on shared hosts 2. A metric ton of legacy codebases that plain don't work on PHP > 5.5 3. PHP 7 had quite a few breaking changes, like you mentioned 4. Laziness