Am a googler (hence throwaway account) & I can easily tell you why this shit keeps happening!
Google featureless ZERO penalties for fucking shit up! Zero! Do you know what the people who wasted two years on Allo got after it was canned? Nothing! Some of them actually got promoted!
Google GREATLY encourages "launches" - releasing something publicly. And keep in mind - no penalties if the shit is half baked, not working, only works on chrome, or some such nonsense! This is the norm!
Why? Promotion. You cannot get promoted beyond a certain level in this place unless you "launch" something big.
So what do you get when you add of all these perverse incentives? Nine thousand, eight hundred, and eighty-three chat apps, and a never-ending chain of redesigns and relaunches so some people can get promoted.
Do you know how many bugs you need to fix to get promoted? Infinity. No matter how many you fix, it will never get you enough "impact" for promotion. Never.
How many useless redesigns do you need to launch to get promoted? ONE!
Extra fun: people internally usually warn about this shit, complain about it, file bugs about shitty performance, etc. It is ALL ignored. Most people who've been here for over a few years have given up filing bugs even. Because the reply is always the same: "you're not the target audience"!
And we all know it! We all do! Some quit when they realize it, others just begin optimizing for promotion as opposed to optimizing for what is good for the user or the company. And this is how you get new gmail, for example.
EDIT: replaced underscores with proper profanity as had been requested