I actually stated this on the post, but let me reiterate, I think that naming things in somehow fun way is totally okay as long as it stays relevant to what the tool actually does (you can have this achieved by play wording suffixes (Mongo"DB", Open"SSL", Ma"git" are good examples, all are better than elephant, dog, and beaver).
Indeed. This helps me know that I'm using a database more modern than Ingres. I chose not to use Oracle or SQL Server because they might have predated Ingres.
Just one question: what's Ingres, and why do I care about it? Of course, I don't, which makes Postgres no more useful of a name than "fluffnutz" or "hooxup". That said, over time, I've come to like the name Postgres.