The comparison is meant to be functional - not technical. Most people use Redis as a low-latency key-value store either for write-heavy uses, short-term storage or as a cache. SpaceBase is, indeed, not a key-value store, but it can now serve the same purpose Redis does, namely, a low-latency, write-heavy data-store, only for spatial indexing rather than key indexing. I think I've made an apt, fair analogy.

By your logic I could call memcached a "schemaless Redis" and it would be not only fair, but apt. Give me a break.

Redis is a particular product, not a catch-all for low latency in-memory data stores. So saying your product is a Redis (which you did, rather than making an analogy) was merely embarrassing attention grabbing marketing palaver which does discredit to your product and suggests that you don't have the attention to detail and critical thinking skills required to properly implement a product in this space. See: MongoDB.