"Germanic" is an offensive term

[Peterski]

It is known that it means neighbour and is a Celtic word in origin.
Roman Emperors adapting the name Germanicus made sure to name us in a neutral way before attribjting such cognomina.

Weren't they called Germanicus posthumously or while alive but by the people?

Many rulers acquire their nicknames posthumously, or people call them names.

The bacterial meaning probably had nothing to do with it lol

Why did Carl Linnaeus call German cockroaches like that, Blattella Germanica?

Interestingly, in Polish their name is Karaczan Prusak (Prussian Cockroach).

[Peterski]

One theory is that Carl Linnaeus (himself a Swede) did not like Germans:

https://www.quora.com/Why-do-we-call...ach-in-Germany

"Possibility two:
These cockroaches are plain nasty. Also Linnaeus was a rather picturesque and temperamental fella. He had the habit of naming pesky animals and ugly species after some of his ‘personas non grata’. For some reason he might have had inclinations against the germans and named the pest roaches after them. Being rather funny, the scientific name took on to trivial use. This is in line with the fact that the same roaches are often called after other nationalities, elsewhere called French cockroaches (e.g. in Portuguese) or even often locally known as Chinese cockroaches. I think possibility two is much more likely as it agrees with more facts."