Well it kind of depends.
Some have the social standing to walk into a Fortune 500 company with a D average and become VP or partner with catlike quickness.
The rest of us need "something" to make up for lack of pedigree. The chances of me, as a civilian pilot with no degree being in his sixteenth year at Southernjets are exactly 0%
The price of wanting to be in a position where I could choose where I wanted to work instead of settling for a second of third tier carrier was being as competitive as possible. And that included secondary education.
For most of us, a college education helps level the playing field. If you're one of two guys going for a job at Southernjets, one is the son of an active pilot and the other is a high school grad, the legacy is going to get the job. Now if you're an Auburn or USNA grad, you'll be much more competitive. That's the way it was explained to me.
I can understand some frustration with this, having never attended a "worthy" school in some people's minds. An undergraduate degree in a worthless subject, from a worthless state school, and a law degree from a worthless, unranked law school. I've been told, quite clearly and directly, that the degree I'm about to have conferred isn't worth the paper it's printed on, and is the cause of all of the ills in the legal profession. Don't pay any attention to the fact that my school has been graduating students out of their law school for 100 years; they're not ranked, and thus worthless.
So this applies to more than just the online vs. brick and mortar school discussion, it's a multi tiered level of arrogance in some ways, with each tier looking "down" upon those that they believe are not worthy of what THEY did to get their degree.
So when you put time and money into an education, after a bunch of folks told you to put time and money into an education, only to have somebody say, "Oh we meant a school that WE, the EDUCATED class went to, or at least played football against on the weekends," it can be frustrating.
But the fact of the matter is that you're right, and Mark's right, and the HR department's are right. Brick and mortar requires a certain level of investment, and it shows that the school is serious about its mission. Additionally, going to an actual, physical school changes the dynamic. The problem with online education, at least at the undergraduate level, is that you learn a lot by BEING THERE, and having to INTERACT WITH PEOPLE, on a FULL TIME basis. College isn't about "book learnin'" in the some way that being an airline pilot isn't really about stick and rudder skills. Important and necessary? Without a doubt, but it's a package deal, and you've got to have all the right components in order to really be successful.
Frankly, there's a reason that the ABA has refused to recognize online law schools for primary (J.D.) education (some exist for Masters of Laws programs, which are much more about straight academics): Nobody has had to stand up in their living room, while "taking a class" online and get their butt chewed for 30 minutes by a professor about the nuances of negative servitude in property law. Without the actual face to face experience, you're losing a whole heck of a lot of the point of being there.
So, TL;DR, I can understand people's frustration, it's very real and palpable. That being said, there's something to be said for going to a "real school" for a set period of years. I don't fly airliners through my computer using flight sim while I eat bon bons on my couch, and as such, I would expect an airline to want my experience to mirror that of which they want to hire me for.