I have to disagree. At some point in your 30-40 year career you may well want to leave the start-up treadmill and join a big company. At that point you'll hit HR pay-grade limits based on your degree (or lack thereof). Big companies do sexy work too. You'll also be un-attractive to start-ups once you get over 40 because, well, you're old and they're not.

Have a friend in his 40s having to plough through a degree (while holding down a full time job, and family duties) for just this reason.