«If I create a microphone does the microphone not exist before it is paid for?»
Actually, to create a microphone you need tools, parts, some kind of work area, in a word: capital.

«Profits are irrelevant to production.»
They are if you want to keep producing.

«The shelf stocker doesn't check the corporate balance sheet before stocking the shelf, nor do the workers from the miner to the delivery guy to the consumer.»
He checks his pay stub. That's part of his own balance sheet.

«Only the wealthy, and their dupes, worry about the accounting department falling in a lake, or taking the day off to fly kites.»

You live in lala land. Even in the good ol' days before capitalism people had to work to eat and they didn't eat so well and they had no computers to complain about it on Steemit.