"Where does supply come from?"
"Mathematics yeah"
Seriously, never speak in public again.
But thx for the laugh
Honestly I don't understand this criticism. Making good answer to that question is _very_ difficult. When I try to explain it, I usually fail, even when the counterparty is total programmer nerd. Then I resort to "you have to research it yourself from internet, start with the wikipedia article" or something. I usually ask if concepts such as cryptographic hash function and public-key crypto is known, and rarely even this is the case.
And usually these finance people tend not to be very math/crypto-heavy, so trying to explain it would have been only distraction.
It isn't that hard to explain and can be done without any low level explanation of cryptographic functions. Here is an example. If the Q&A is at the end of a presentation which explains transaction processing this explanation can be simplified further. Then again if you go up there with a single slide which provides no useful details then you are setting yourself up to fail.
"Where does the supply come from?"
Miners are transactions processors. Miners protect the network and validate transactions. As compensation for that service, when a miner solves a block of transactions they receive a subsidy from the network. The subsidy began at 50 BTC per block and is cut in half roughly every 4 years. The subsidy halving will continue until it reaches zero and all coins are minted. The network self adjusts so that regardless of the number of miners perform transaction processing, a block of transactions is solved on average every ten minutes. The primary distribution of coins is to miners in the form of block subsidies. The secondary distribution to non-miners occurs when miners trade coins for goods and services (including other currencies).