Upvote:2
The primary reason for doing it on your own is usually lower cost and more flexibility.
The primary reason of doing it with a guided tour is the local knowledge that your guide can share with you.
So a traveler needs to decide, do they want to save money and just go look at it, or do they want to come away with an insiders understanding of it. And no, Lonely Planet is not a good substitute for a local guide's knowledge (my apologies Tony & Maureen).