The problem is that getting top to start can take a long time if it's actually thrashing heavily enough.
I'd agree that the LED is nonessential with HDDs -- you can just listen; and then you can even make out whether it's doing a lot of seeking or long continuous accesses, but you can't do that with SSDs.
If people can perform remote admin on machines 1000s of miles away without the need of green LEDs, I'm sure consumer tech will do just fine.