Then people would have complained even more about BotW's world being empty.
All right, then I'll answer the thread title's question. No, I don't personally feel BotW overdid anything.
If they had done that, maxing out your inventory would have been harder, as you would have to collect every single seed. Putting twice as many as necessary allows for a margin of error -- you can miss half of them and still max out.
I don't think I should have to explain why looking for 20...
I don't get where the complaints about the Korok Seeds come from. If they had put less seeds, finding them would have been harder and more time consuming, given the massive world. It would have been like searching for a needle in a haystack, even if expanding the equipment inventory took less...