It isn't a 'design problem', the battery is wearing out and you're faced with two options:
1) Don't throttle resulting in a phone that spontaneously shutting down.
2) Throttle the phone and people can keep using the phone but find it slightly slower.
If there was one thing that Apple did fail to do then it was explaining to the end user what they were actually doing which would have avoided the fiasco in the first place. Btw 'no Android blah blah blah', we don't know what is happening in the Android world, there could be people just finding their phone isn;'t reliable, they take it in and get told it just needs a new battery. Maybe Apple should have just decided not to throttle and tell customers, "hahahaha, sucks to be you, you need a new battery". Btw, how about reading what I actually write instead of pulling stuff out of your ass - it is clear that I am not bringing up Android as a diversion but actually pointing that this is an industry wide issue that needs addressing and there needs to be a broader investigation into practices within the IT industry regarding planned obsolescence.