This.
You drive to the coniditions, not the sign.
What if the conditions are fine to do 60 and they are doing 30? We've all been there, I know it's only a small annoyance and we should sit back and relax, but the reason they are doing 30 in a 60 is there not capable of reacting normally to a normal situation, and hence the OP's post. Old people going too slow means that they are incapable of normal driving and they shouldn't be on the road.
Would you let someone do 30 down a motorway??
