Another friend truly does have a terrible manager. He's been with his company for 5 years and had consistently great performance reviews until he transferred locations. Six months later there's a position at a different location and they won't let him transfer and he's getting poor reviews with no suggestions for improvement. He's thinking about quitting and getting re-hired at the new location. This would result in a pay cut and loss of vacation time but he's willing to do it. He loves the company overall but his current management has made things very difficult for him. That's loyalty.
Then this guy gives examples of a bunch of founders who started immense companies and stuck with them. Of course founders are going to be loyal to their company. They're the founders.
Now for this example he gives:
You start fighting with your co-founder whom you thought you understood. Your revenues are “just around the corner.” Your angel investors are nervous because the VCs aren’t moving that fast to fund your next round.
As an employee faced with that situation and with a better offer standing, which would you go with? The company you're not sure is going to be around because the founders are arguing and the capital is drying up or the one with money to pay you more? I'm not sure why he used that as an example.
The author of the post seems to expect a lot from people he describes as feeling entitled.