The big airport crybabies are usually those who expect weather or mechanical problems to vanish by voice command. Unless you fly Spirit, I've seen minimal problems with airline staff or TSA agents. Most are fairly friendly.. of course this may vary by airport. I usually fly in and out of the same handful.
To give just one example, in Europe, passengers are not routinely required to remove shoes.
That means either someone was not following protocol, they were running an experiment or you were in business class. Shoes need to come off in standard screening (1). Such anecdotal evidence means nothing. I for one had to take off my shoes a month ago (a long with all other passengers) but I never had to remove my shoes when flying inside the EU.
That's just a website of things they recommend you do. It doesn't look like any kind of official policy document or protocol. I mean it also says 'give yourself enough time to arrive at the airport early' but that's an official protocol is it?
In my experience, the TSA experience is consistently inefficient, with (occasionally severe) bottlenecks. But more frustrating than inefficiency is a sense of apathy radiated by many TSA agents.
Whereas the airlines compete to serve us, the TSA feels vaguely like a slaughterhouse, in which we are the livestock.