That's sort of true, but the default state mechanism (session files) doesn't scale well, or even work across load balancers that don't maintain server affinity for each client. Scaling a PHP app isn't hard, but it can be non-trivial if you've written the code without considering scaling. Other serverside scripting languages (Python, Ruby with Rails) nudge you in the right direction in ways that PHP doesn't.
That's sort of true, but the default state mechanism (session files) doesn't scale well, or even work across load balancers that don't maintain server affinity for each client. Scaling a PHP app isn't hard, but it can be non-trivial if you've written the code without considering scaling. Other serverside scripting languages (Python, Ruby with Rails) nudge you in the right direction in ways that PHP doesn't.