I enjoyed reading your defense but you miss the point about the debate which is not about art as an intellectual pursuit but as an industry with a financial underpinning. How that financial aspect of the art market works when compared to the stock market is where there is a troubling disconnect.
As I see it, the financial market is made up entirely of dealer/brokers who may or may not be ethical in their advice and knowledge. The art world has that too, but also incorporates the larger influence of an auction process that is built specifically on deception (chandelier bidding, etc) and conflicts of interest (buyer’s premium, ownership interest in auction lots, etc).
The component of an unregulated duopoly (Christie’s/Sotheby’s) in this market is responsible for tilting the public dissatisfaction that you experienced at the debate.