Well, you don't have to ignore Greece has to offer when you stay in these two hotels. I don't know how you came to that statement. Amanzoe is close to Mycenae, Ttiryns, Epidauros and also Nafplio. These are not insignificant things and you can do a lot more. You can also visit Corinth on the way. MO is very well located for Olympia, and Messene, Mystras and Sparta are also within easy reach. There's a lot more here too, I can just think of it off the top of my head. It never gets boring.
I have already explained the purpose of the resorts near Athens. On the one hand, you can do some things around Athens more comfortably from there, and on the other hand, you have a beach to balance out the city.