If the majority of bitcoin-exchange market supply is coming from mining, which currently seems to be the case,
Not at all. Not even if we assume miners selling every coin they mine.
Source: blockchain.info
and that supply halves, that's a supply shock. If demand remains the same, the price must roughly double.
A fundamental misunderstanding of how the market works.
If that was really the case, GM could simply cut the number of cars manufactured in half, and double the price. Profit!
Really comparing bitcoin to cars???
If there were only 100 cars in existence and there would never be any more, then we destroyed 50 of them , yes, the price of the remaining cars would skyrocket...
err yeah, if Biitcoin was the only money in existence, or even the only crypto...
But let's work with your example: "If there were only 100 cars in existence and there would never be any more, then we destroyed 50 of them , yes, the price of the remaining cars would skyrocket..."
No, it would not. People will learn to walk, or ride scooters, or trains, or fly. Other car manufacturers would appear (just like other coins are appearing).
You're starting with the same misconception that Beanie Babies enthusiasts fell victim to: Limited supply guarantees value. Of course, it doesn't. I don't need to own a Beanie, and I certainly don't need to own a bitcoin--I can chose to simply ignore both & use my CC.
Bitcoin may not be the only coin out there but, it's the only one with a massively giant network behind it.