Because Face ID is far inferior to Touch ID (the reasons have been mentioned many times in this thread so I won't list them again) and that's very unlike Apple. Killing off MagSafe on the MacBook was baffling enough but at least there's a few third party options to fill the gap. The notch looks bad, but most people get used to it after a while, just like people got used to the ugly camera bump that iPhones have been marred with since the iPhone 6 (most people use a case anyway). Besides, the notch is another workaround that will go away as soon as Apple has figured out a way to integrate its sensors and other components in a more practical design. The headphone jack isn't coming back either -as shown by other manufacturers getting rid of it in their handsets as well- but similarly to the notch it's a temporary annoyance (until most headphones are wireless?) that can be "fixed" by third party dongles. Face ID on the other hand is a downgrade that leaves users with the option of going back to the pre-Touch ID days of the passcode (or worse, no passcode at all) or to go find an Android phone that'll work for them.