[derivativethrow]

It's probably getting downvoted because it's not actually relevant. I'm not sure why there are so many comments here talking about refusing to interview or "rejecting" recruiter advances. The OP was very specific in wanting to hear from people who rejected an offer for another offer.

Instead a lot of these comments are from people who seem to have an axe to grind against the companies themselves. It's fine to have ethical or practical disagreements with FAANG companies, but it's not relevant to the OP's question about why someone would go as far as receiving an offer and then decline to accept it.

[Goladus]

To be fair, the narrow question would have been far more compelling 10-15 years ago, when these companies were both less-huge and had largely unvarnished reputations as being the best large companies for software developers to work. 10 years ago, sour grapes would have been a lot more obvious and valid answers would have been quite interesting. Today, not wanting to work for Google or Facebook is rather mundane.