I think you're still misunderstanding.
What he means is this:
The exact moment he decides (in his mind) that he is finished with a composing a text message/response, he instantaneously stops typing the message AND SIMULTANEOUSLY hits the SEND button—only to discover that NOTHING (then) HAPPENS (for the next approximately 1.5 seconds), and …. (ONLY) THEN does the device (his iPad) send the message.
Everyone else (and he on his phone, as well) does not have this problem: they hit SEND and the txt message immediately gets sent.
As for your dismissive "I think you need to relax" sentiment, my counter to that is this: we are testers, we are objective, and (unlike you) we do not underestimate the huge negative impact on productivity in both personal and business contexts that latency has.
Latency is a huge issue. You can metric it and discovery that a task that normally takes, say, .01 seconds for the machine to execute, is unfortunately now taking 1 second to execute; and that has a very real impact on worker productivity.
This guy's rant is fully justified. It would be like buying a car with ignition latency so poor that you had to wait 1.5 seconds AFTER you turned the key for the engine to start. Would you accept that? I don't think so. Would you accept waiting 1.5 seconds AFTER you turned the faucet for your bathroom sink fixture to respond? I don't think so. What if I'm making a left turn in front of a semi while at speed of, say, 30 mph? A 1.5 second delay on response from my steering system is now responsible for my death. Get the picture?
The struggle is real. Please don't trivialize the problem.