The story is that Amazon sacrifices engineers and others after every big project, success or failure. They have developed a weird human sacrifice culture. Fire phone? It was a failure implementing Bezos's wacky ideas. Engineers had to be purged to atone for it. Fire TV? Huge success but we don't want engineers getting any credit for it. Result: purge some engineers. Echo? Another success that now had to float all tho…
This startling quote is in the article : "Many of the people who helped create the Echo no longer work for Amazon..." As you say, it sounds like success gets punished at Amazon.
Plus it's amazon, you stick around you are probably gonna end up doing oncall ops BS.