Why is this sub-optimal? People may not like Cockroaches but they definitely have a reputation for durability, which isn't a bad mental link for a database company. It also provides an identity & personality which is so often missing from modern companies. Maybe they've found they get more from those who really like it than those who really hate it (or maybe they just like it themselves).
It still has a negative connotation. That's unavoidable.
People don't like cockroaches.
From a marketing point of view, it is a very bad name.
Unless the perception of cockroaches changes, which is rather unlikely.
If you pick a happy name, you get complaints that they sound too generic, sound like a medication name, etc. People also complain if your name ends in .com or .net, as apparently that sounds like something from the mid 90s.
People just like complaining about names.
On the other hand no one brings this point up about Oracle, PostgreSQL, SQL Server, MySQL, MariaDB etc.
People like complaining about names that they wish things didn't have.
My problem with SQL Server is that the name is so generic it sounds more like a product category than a product. Its like naming a word processor "Text Rendering Engine". Microsoft seems to be generally terrible at naming things: I don't know how they expected people to keep .NET Core, Standard, Framework, and Mono separate, not even counting how bad a name .NET is in the first place.
It also has the advantage of slightly-less-technical people thinking it is the SQL Server and there's no other options.
I’m not a paying customer so my anecdote maybe isn’t useful, but there’s so many databases that typically I just brush them off, but this one grabbed my attention because of the name.
Also, Dung Beetles Navigate Using the Milky Way.
Still wouldn't call my new browser Dung Beetle...
I'm sure even you'll admit that they have a rather cute looking cockroach as a logo.
For their target market, I don't think their name matters nearly as much as you think it does.