It's hard to donate the money you don't have

The correct answer

see https://www.carnegie.org/about/our-history/gospelofwealth/

Also, Perlis was talking about computing, but his aphorism could equally well be applied to winning the rat race:

Dealing with failure is easy: Work hard to improve. Success is also easy to handle: You've solved the wrong problem.

To be considered a philanthropist, one has to have a lot of money in the first place. Even if I donated every cent I earned last year, I doubt I could get a building named after me.

Is this a real question?

(Note that your list is very heavy on self-made billionaires. Vs. the "daddy left me gigabucks" crowd.)

Once you've got a few 50-room mansions, the 400' yacht, 3 private jets, 2 vintage car collections, and whatever other "meh, just a few billion?" trinkets that your tastes might crave...there still are the "always yearning to control more things" urges that helped drive you to become a billionaire to begin with. And the desire to add another dimension to your exalted social status. And your PR team regularly pestering you to give them favorable-sounding stories to push.

10-digit philanthropy, especially ostentatious and self-directed stuff, can help meet a lot of those needs.

Why are there so few?

They're following the well-trodden path of after-the-fact philanthropy practiced by robber barons (Andrew Carnegie, John D. Rockefeller) to clean up their public image following unscrupulous business practices that brought them those billions. Less cynically, there's only so many things one can spend money on, and philanthropy is least controversial.

There's effective philanthropy and then there's performative philanthropy.

First off the rank, Bill Gates, is genuine (to the best of my knowledge) in his efforts to address global disease etc. In this he appears to be relatively effective in the sense that much of the money going in to this venture is having an on the ground real world spend on the target problem.

Then there's performative philanthropy.

How the Ultrawealthy Use Private Foundations to Bank Millions in Tax Deductions While Giving the Public Little in Return

https://www.propublica.org/article/how-private-nonprofits-ul...

    It’s a simple bargain: The rich get huge tax breaks by donating art, property and company shares to benefit the public. But some donors collect millions while offering little or no public access.

There are many such articles and there are a number of variations on a theme; money goes to Foundation, Foundation has high costs for services provided by other companies owned by family and friends, money is recirculated within a closed system with less money going to any actual charity work than taxes that might other wise be paid. Throw in a bit of dark money laundering, buying fame and good will, etc.

There are real philanthropists, there's also a lot of other activity masquerading as charity.

It is one of the only ways to spend this amount of money to shape the world based on their thoughts without getting more (deserved) hate.

The answer is the same as to the question "Why a cat licks his balls?"

Sarcasm?