We have all seen things like the typing system of JavaScript (There is a funny post including a truth table somewhere around here). I consider this one of the main things that makes a programming language bad.

Other things that spring to mind:

• Bad Error messages (Either obfuscated so you can't figure out whats wrong, not existing or simply too long and red)

• The language wasn't planned and just grew uncontrolled in all directions (PHP?)

• The language encourages bad programm(er/ing) habits such as: Global variables everywhere, bad variable names

• Inconsistent naming conventions inside the language

I can't come up with any more at the moment and would be very happy to read what you think about this.

• What shouldn't be missing in a language created to be as bad (from the perspectives of the programmer, the company that hires to programmer, the team leader and the customer) as possible?

(I ask this because I'm designing a bad, experimental language at the moment)