How Bad Are Singletons?

Question

So ....

There are obviously many questions that all have been asked about Singletons, Global State Variables, and all that great stuff. My question is,

Answer 1

1. Global variables and singletons are popular because they are simple and convenient.
2. Dependency injection, the only reasonably convenient replacement for global things, is still rather unknown in the PHP-community.
3. The PHP-community often prefers simple hacks over proper solutions.
4. Many PHP-developers are quite clueless about programming and know barely enough to make their programs work.