Undue credit
From the description of their "proprietary" technology, it sounds like they actually did very little. It sounds like the took MySQL Cluster (in-memory storage, distributed and replicated data sharding for scalability, and on disk storage only for crash/reboot recovery) slapped a trendy sounding name on it (there had to be X in the name), and call it a revolutionary new product.
The simple fact is, unfortunately, that MySQL Cluster is actually slower on any low-latency load, and while it is a clever technology suitable for some use-cases, it doesn't come without drawbacks.