You're not talking to technicians. You're talking to 'service advisors'. The people that answer the phones don't fix cars, and most of them have zero technical understanding whatsoever, but they do have to deal with everyone coming in for service as well as everyone calling to try to schedule it. It's thankless concierge work with a lot of turnover, and a lot of dealerships are still as chronically understaffed as the rest of the world.

Spend a few weeks telling people you're scheduling appointments into next year, and getting yelled at because the lot porter-turned-greasemonkey has been doing 6 quart fills on 5 quart reservoirs all day, and see how long it takes before you turn into a smartass. It's not their fault, it's the organizations that are so concerned with profit that they don't give a shit about their people.