That's basically saying that anything that's not a 100% original idea can not be considered a great idea. There are plenty of things that are built on existing

That's basically saying that anything that's not a 100% original idea can not be considered a great idea. There are plenty of things that are built on existing ideas but the execution is part of it. An idea is useless without good execution and there's no real reason to credit people on ideas, lots of people have good ideas but almost none execute well on it. For example there were plenty of online mapping companies available, but when Google Maps came out they completely dominated because their execution was so good. It's crazy to just reduce that down and say it wasn't a good idea just good execution.