It has nothing to do with the president, because he hasn't got the power to do anything without the socios approval. And the majority of the socios are older folks who take pride in Barca's-catalan history and their membership model. It's absolutely impossible to convince the current generation selling even one part of the club, no matter what a president might say.
Pretty sure even proposing such a thing would immediately result in a vote of no confidence. How it might look in 20 years, when many current older socios will die of old age and the generation shifts a bit? Who knows, but now it's absolutely impossible.