Since they are getting contributions, gifts, and grants, I don't see that as a shortfall...That's like saying the SI has a huge shortfall because they get all their support through contributions.

Yes. It's pretty much exactly like saying that. If you had read the OP then maybe you would understand why I made the point I did, or indeed why Merkle made the comment he did....

Many supporters of cryonics are ultra-wealthy. The second the material existence of Alcor is threatened, they'll contribute.

One would hope so, as opposed to switch to CI or wait just a little too long in the game of chicken or anything else.