Do you want to go work somewhere and write Java programs for a living? Maybe you'd like to go write games or work on an office suite? Then learning high level languages like Java will serve you well. Do you want to write low level stuff and do "real" computer science? Maybe you want to develop a new high level language, or do hardware development or other significant development. If that's what you want to do, then you're right. High level Java and other languages should just be a footnote. Focus on Math, assembler, maybe some C/C++. Other low level work that provides a good foundation would also be wise.
Both of those are "Computer Science" disciplines in the modern sense. Obviously they are significantly different from each other in both required study and expected results.