Keeping a PC running when you aren't doing anything with it sounds like a waste of electricity to me.
Electricity also wears down electronic components, so I think it also shortens the lifespan of your PC parts.
How much power is consumed when suspended?
I can't remember the last time I got a new PC because the old one broke, vs. because I wanted one that was better.
As for being wasteful, sure, but it adds up to an insignificant rounding error of my total energy use so it's not something I lose any sleep over.