This is not a fair summary. I have several friends (especially online, who I communicate with via asynchronous email/chat) who are technically competent and lovely people.... but who I would not ever want to have as an in-person lecturer/teacher, because their accents are extremely difficult for me to follow. In spoken communication one or both of us have to constantly repeat ourselves, idioms differ between us and sometimes intended meaning is severely misunderstood, and overall communication is slow and difficult on both sides. In some cases my friend speaks English as a second or third language and feels awkward/uncomfortable speaking English face to face at normal conversational speed.

In a classroom setting, there is usually some technically difficult material to be learning, and often a course is structured so that the first concepts taught are essential building blocks on which the rest of the course relies. Trying to simultaneously decipher a thick accent and learn demanding technical material will put a student behind their peers who are taught by someone easy to comprehend, and might make the course dramatically more difficult.

It is neither “racism” nor “laziness” to want a teacher who is a fluent speaker of a form of speech you can easily understand. Just simple pragmatism.

> I've seen this a million times teaching students.

If most of your students are complaining about your accent, is it really a fair to conclude that they are all just lazy racists? Maybe you could work harder on developing an accent comprehensible to natives in the place where you are teaching.

I would lengthen that list to part inexperience, part laziness, part racism, and part a real problem.

College students are one of the stereotypically worst groups for this. They often have only really experienced one accent and racial group - their own. And suddenly they are being taught by people from another country with strong accents. So inexperienced and lazy are likely, while racist is not rare.

By contrast in tech, you have to work with people who have a variety of accents of different kinds and strengths. And frequently this happens over the phone with outsourced teams. The variety is astounding. For example I'm dealing with countries from Paraguay to Vietnam in my co-workers, and regularly deal with have outsourced contractors from India to Poland. I don't have trouble with any of their accents.

When experienced tech people like me give up on trying to understand you, it is unlikely to be inexperience, doubtful to be laziness, and probably isn't racism. Which means that you likely have a real problem.