The train of the discussion, if you go and read the OP's link and inner links, is like this:
- Singletons are bad
- Why are singletons bad?
- They're not "real" OO, they're global state, they obfuscate dependency, etc, etc, etc
- But what if I just legitimately have a ton of global state?
- Use a database! Use a filesystem!
The last point in the chain admits that the first point is mistaken. "Use a database" is just saying "use someone else's code to solve your problem". What if the database is implemented using singletons? What if it uses code that isn't OO at all? All you've accomplished is to say "OO can't solve your problem, use something external". In fact, my problem is solved just fine by using a singleton.
The train of the discussion, if you go and read the OP's link and inner links, is like this:
- Singletons are bad - Why are singletons bad? - They're not "real" OO, they're global state, they obfuscate dependency, etc, etc, etc - But what if I just legitimately have a ton of global state? - Use a database! Use a filesystem!
The last point in the chain admits that the first point is mistaken. "Use a database" is just saying "use someone else's code to solve your problem". What if the database is implemented using singletons? What if it uses code that isn't OO at all? All you've accomplished is to say "OO can't solve your problem, use something external". In fact, my problem is solved just fine by using a singleton.