Because, despite having left ages ago, he was part of Apple at one point so he's of course an expert on all things tech, double if it's Apple
And since he was part of Apple blogs can put that in the headlines and gets more hits.
Frankly I wish folks would stop asking him and I wish he would stop answering. He was there to speak about a totally different topic and should have refused to talk about anything else out of respect for the folks that invited him there to talk about their thing
Double when it has to do with what policies etc Apple should have. He knows nothing about how it has been run for the last 15-20 years so he has no business speaking about flawed policies, what their motives are etc