I'm a modern programmer, probably, and probably only a modern one. I started learning programming with Python and C, but CoffeeScript is the first language I learnt to use. By teaching JavaScript, almost the all the guides does not talk about the memory cost and CPU cost. Because it's a scripting language. I prefer not to call it lazy because we have our problems to solve and storage is sometimes not the biggest problem.
When it comes to large simple page apps in JavaScript, the performance issue becomes significant too. Yeah, we are JavaScript programmers and most of us does not have a solution but only refer to the browser vendors for help, like making V8 faster, or pry that React Angular Vue would be faster. You call that lazy? I would say maybe on this aspect.