Elastic has iterated over and over, taking years to remove obvious problems with their products, building heavily on the community for input about their needs, but still managing to ignore them for a long time. I still remember searching for anything that's not Kibana since their interface has been dreadful (and probably still is). I remember people turning away from Logstash to Fluentd and others pretty early, but don't know the exact reasons. I remember when pretty important and frankly "core" stuff like authentication and authorization among others moved into Shield and other specialized commercial plugins.
They have leveraged almost a decade of developer good-will to cope with their inherent architectural problems and to fight for introducing "weird open source software" in their respective companies and ultimately give them their street cred of "logging aggregation == ELK". Now, after most of their stack "just works" like people expect it to, they throw it all away, putting people who fought for them in license jeopardy while pointing the finger at Amazon? I don't have any sympathy for this. It's your business, if it fails, nobody is at fault but yourself, especially if you a 14B behemoth. May the exodus begin, it's long overdue.