[zmmmmm]

My best analogy for this is to think of Java as like a truck and other languages as like vans (C++) or motor scooters (python, etc). Past a critical threshold Java has absolutely amazing performance (sits in same league as C/C++) but if you imagine driving a large truck around town ... you are constantly starting and stopping, turning into alley ways etc - a truck is not going to do too well. But if you actually have to deliver 50 tons of goods, good luck on the scooter. And a well designed Java app can behave like a scooter but its not the default setting because most people in enterprise settings have truck-like problems.

However the slowness of Java on the desktop is a bit overblown by people's past experience I think .... improvements to garbage collection and hotspot optimisation, and elimination of applets have certainly made a big difference to the type of stalls that used to make people say these things.