You can of course find anything annoying. But you said that it's annoying that people choose to do this, and you called speaking without vocal fry "speaking nor

You can of course find anything annoying. But you said that it's annoying that people choose to do this, and you called speaking without vocal fry "speaking normally", implying that it's somehow wrong/abnormal and they should stop. Similarly, it's perfectly OK to find some accent annoying, but it's not OK to say that you wish people would stop using their accent and "speak normally". And while of course you can do vocal fry or not, once you've established a pattern of speech, it's very hard to change. You can try speaking a whole day only with vocal fry and see how often you'll slip back to your regular speech pattern, and just how weird it will sound to you. Or try saying "aboot" instead of "about" for a whole day, if vocal fry sounds too annoying to you to try out (which, again, you're perfectly entitled to). Either way, the discomfort you'll feel trying to change your speech is exactly the same discomfort someone like your colleague would feel.