I often tell my dev colleagues to avoid having their PC turned on all the time, be it because of the electricity bill cost, environmental impact or simply to make the longevity of the hardware a little longer. Granted almost everyone just ignores those things even if they're conscious of it, so I'd say you're right

There's pros and cons on the longevity side. 24/7 use causes more wear to mechanical parts (fans for instance) but can be better for the electronics, as heat cycles are a big part of the problem there.