This is not the case. Maybe people have already forgotten what using computers was like when everyone had only 1 core, but having a few desktop apps pegging their share of cpu doesn't hurt interactivity much even on single-core computers.
>>MBCook+PD1
I’ve had a mouse cursor move slowly when doing some tasks in Chrome. And all other apps barely reacting. Still a mystery to me. I hope that was not a sign of some backdoor being installed through a Chrome vulnerability.