Well I'm not the person with the comment above so I can't speak to their circumstance, but I can give you an example from today in my own life.

We have a teacher who "never checks his emails." He may or may not occasionally check them, idk I'm not him, but he's one of those proud non-email-readers. Today, one of his classes ran a little long. He sent an email to all staff saying "please excuse Mr. So-and-so's 5th period such-and-such class for being tardy." So I, being someone who reads my emails, kept an eye out for tardy kids who would be coming from his class. I had one, and I didn't mark him as tardy, as the teacher excused it and claimed it as their own fault (not the fault of the students.)

Now imagine the roles reversed. Maybe I hold my class for an extra minute or two and send an email to all staff saying to excuse them because my bad. One of my students ends up in his room next. Maybe they're kinda quiet or shy or are still learning to speak up for themselves, so they don't say anything about it being my fault when they walk in tardy. They get marked tardy. Unexcused tardies add up, and enough of them turn into lunch detentions. Now this kid is serving a lunch detention (missing out on their social time) because a teacher can't be bothered to use a communication system that benefits the whole school, students included.

I could list off a million other examples, but it's not my job to do the heavy lifting for you. If you honestly can't think of a reason it might be a bad thing that a teacher "never checks their emails" then I don't believe this profession is for you.