Then don't multitask w/a ton of apps open. Problem solved. Same principle as multitasking on a computer. Humanity survived when multitasking was new to desktop computers and I think humanity will survive multitasking on mobile devices.😉
Problem not solved, you don't have to rely on your computer for important phone calls, texts. I guess in the future, I can see Apple figuring out a way to not compromise reliability, still allow for virtually unlimited amount of apps, and include multitasking, but I really don't care at all. There will always be other functions that people will complain about not having, then the next generation will have it, though I don't see Apple changing this one for a long time.
Not Lethal.