Wow, not so fast. I'm a Stanford grad and I donate a bit of money every year when they ask. Should my future kids be excluded from admissions? There's a world of difference between donating and donating to get your kids admitted.
These elite schools all have massive endowments, on top of the ridiculously inflated tuition they charge, so give me a break if you're trying to tell me they need these donations.
Otherwise, the idea of an elite school on your resume "signaling" something about you is meaningless. These schools are supposed to be bastions of knowledge and research, not expensive country clubs for rich kids to network with each other.