Memo is a centralized website. It only picks up people who have registered an account. We need open source software that reads the blockchain directly.
In theory, it should be as simple as filtering tx's down to ones with OP_RETURN data tagged with a Memo footprint, linking those posts to an address profile etc.
Maybe like an index? A decentralized network of existing Bitcoin nodes that index the blockchain for memo posts and profiles and feeds that data to clients. Memo nodes if you will.