Because those devices run Android Java, which Sun saw $0, thus not able to capitalize on it to pay their bills.
1 - Google did not pay for Java licenses, when it should. Even Andy Rubin admits that on his emails.
2 - To this day Android is not Java SE compliant, thus creating a fragmentation between Android Java and Java. Just like Sun managed to prevent with J++
3 - Being a Java license as Google avoided to be, and still isn't (many Java APIs are not yet available on Android), would have required Android to be fully Java SE compliant
So to conclude, Google tricked Sun and fragmented the Java eco-system.
They should pay and provide a 100% Java SE compliant implementation, or be honest about it and fully migrate to Kotlin, Dart or whatever they feel like it.
1 - Google did not pay for Java licenses, when it should. Even Andy Rubin admits that on his emails.
2 - To this day Android is not Java SE compliant, thus creating a fragmentation between Android Java and Java. Just like Sun managed to prevent with J++
3 - Being a Java license as Google avoided to be, and still isn't (many Java APIs are not yet available on Android), would have required Android to be fully Java SE compliant
So to conclude, Google tricked Sun and fragmented the Java eco-system.
They should pay and provide a 100% Java SE compliant implementation, or be honest about it and fully migrate to Kotlin, Dart or whatever they feel like it.