I don't think that's a mistake. Besides the promise of memory management the "write once run everywhere" promise was a huge selling point of the JVM. So much so that Bill gates famously was terrified of it.

"I am literally losing sleep over this issue since together with a move to more server based applications it seems like it could make it easy for people to do competitive operating systems." [1]

[1] https://www.joyk.com/dig/detail/1672957813119759#gsc.tab=0