Exactly. These days Java can be used for high-performance computing, but in the '90s -- coincidentally, the peak of its hype -- it was enough of a CPU and memory hog to make C++ programmers spit. I saw a paper from around 2000 discussing it, and it unfavorably compared the JVM to Python's relatively lightweight runtime. These days Java actually gets pretty close to C++ in speed, but we still think of it as "not terribly slow."
