[ubernostrum]

If someone is known to have a high level of knowledge on or experience with a topic, then giving weight to that person's opinions on the topic is not a bad thing to do.

(also, I'm tempted to label comments like yours "argument from informal fallacy" -- you've offered no actual critique of any actual arguments, you've just named an informal fallacy, apparently in hope that people will take that in itself as an argument)