"If you see a nice thing, someone is leaving money on the table" is a reason we can't have nice things.
.
Long version:
People seem to think that it is smart and cute to share pieces of wisdom like "if you never missed a plane, you are spending too much time at the airports". Yay, you should optimize everything to signal how smart you are! The part that is missing from the picture is how going later to airports will create some extra stress, not just for you, but for everyone involved. In this sense you are defecting in a multiplayer Prisoner Dilemma -- imagine if everyone started going to airports at last minute! Suddenly it is less cool if your edgy behavior becomes a social norm.
But it gets worse. When the meme gets popular, imagine what happens if all people... okay, that is not realistic, but... imagine if 10% of people start applying the generalized version of same rule in all parts of their life. (These will probably be overrepresented among managers, because it is their job to optimize things.) Why limit ourselves to the airports? "If you have never been sued for sexual harassment... theft... murder..." complete the pattern. Once you have seen it, you cannot unsee it, right?
When the food you bought in a shop makes you sick, imagine that someone in the shop's decision chain realized that if their food never makes their customers sick, they are spending too much money making sure that their food is okay. (If the car you produce never explodes and burns its passengers alive... yeah, you have seen the Fight Club.) Heck, if the food you produce is nutritious, that alone means you are leaving money on table, you should replace the nutritious parts with some cheaper shit, just make sure it tastes approximately okay, or just add more sugar.
"That only shows you can't get nice things for free anymore. But I can still pay for the nice things if I want them." Are you sure? Are you sure someone is not running a calculation that says that making the thing slightly worse in a certain specific way that is difficult for you to detect could increase the company profit, and therefore it would be really stupid of them not to do so? How sure are you that making your favorite product worse in any possible dimension is something you would immediately find out and punish by changing your supplier? "If you have never betrayed your customer in a way they would be shocked to find out..." complete the pattern.
If ethics means anything, it means leaving the money on the table sometimes. Metaphorically, I mean -- I am not talking about tipping here. Actually, the culture of paying your workers minimum wage or less because the customers will then feel bad about not tipping them enough is just another instance of the same pattern.
Focusing on choices that essentially affect only the chooser:
"If you've never been mugged, you're taking too few alleyway shortcuts" would be terrible advice, whereas "if you've never been turned down for a date, you're not putting yourself out there enough / aiming high enough" is generally good advice. So now we are talking price.
Setting aside that doing things that are bad for ourselves is often bad for others, and looking at the specific example offered: To me, missing a flight would be like getting mugged. Or at least, it would be much more like getting mugged than getting romantically rejected by a stranger. If it's a thing that happens once in my entire life, then I haven't spent enough time at airports.