This isn't 100% true.
There are companies out there that have degree requirements for some positions. They don't care that you have 4 years of work experience with no degree. If you don't have a degree, they aren't going to put you into their management track program which is to start off as an assistant manager and being a protege under a mentor, i.e. higher level manager. Now, you aren't completely SOL with four years of work experience, but it takes way longer to move up the ladder, so it's going to suck when Bo-bo, the college graduate clown, surpasses you on the corporate ladder climbing race. You can make it to the top, but you have to be in it for the extra long haul.