What an unpleasant attitude. People have emotions. If they're apologizing, maybe they feel bad. Accept it and get on with your day. A punctilious email etiquette isn't going to improve anything.
For instance my observation is that people in the USA will tend to give you a lot of unrequested information like all their health/medical problems or the sports games of their kid and what not. People in europe seems to be more private unless they are talking with very close coworker they would consider as friends.
Almost nobody writes, "I am sorry I was scrolling Twitter and Hacker News while ignoring my e-mail. Fortunately, I have stopped and now can respond!"
The same for : "How are you ?", "I hope this email finds you well" or worse than everything, Emails Greetings embedded into the signature.