My mom is the only one who ever called me any shade of beautiful. I think we all know what that means. However, if merely the word ugly being on a page can be "harmful", what you really need is professional help, not a change to Python. Because there's obviously been some things in your past you need to work through.
Python and open source have always been more about things like inclusivity and diversity than about excessive political correctness. I'm sure the historical concepts of master/slave were so distant to the handsome young men that developed the computer > science concepts that they didn't expect to cause any naming conflicts.
And not the kind of inclusivity you hear about in [current year]. Open source and related cultures never cared about diversity, they always didn't care about who you were or how you looked, and solely judged you by your work or contributions. I don't use python because Guido or whoever is such a great guy and really worked hard, I use Python because Python is a very useful tool for me. Inclusivity for inclusivity's sake is a bad thing and kills communities and companies. Any charged context is not our problem - it's societies' problem. I'll admit it's a bigger problem, but it's one we need to address through elections, demonstrations, or other political means. Not by self-censorship. Even aside, Python is a world-wide language. Not american or even european. If we have to ban "Ugly" for american sensitivities, then perhaps we need to ban a number of others for china's sensitivities. Where will it end ? Nowhere, it'll keep going on forever. That's why i'm +1 for reverting the master/slave removal PR's.
There are also nationalist jokes about Dutchs. That also must be stopped! Well, we just are superior ;P
(If I wanted to whine, though...."Dutch" isn't what we call ourselves. Etymological, it's root is the same as our word "Duits" or the German word "Deutz" (or something close), which means...German (Duitsland / Germany). Since we had a war a bit ago where we were occupied, this makes Dutch sound a lot like we'd still be under foreign rule by the nazi's. Terrible, huh ? We call ourself "Nederlanders", which can't really be translated, as the country name, translated as "The Netherlands", is already a multiple, so the normal transformation like america -> american doesn't work very well. Strangly, the Germans don't do this - they call us "Niederlanders", while referring to themselves as "Deutschland".)