I grew up with the most varied swear words you can imagine. In fact my dad uses the c word in place of the word 'people' in general. This is what growing up in the rough parts of Glasgow will do. Yet I still count my dad as one the smartest and most creative people I know. He has a brilliant weird brain where he can apply himself to any creative process, pick up any instrument and play it, or a tool to make a piece of art, whether painting, building models etc. So that doesn't really correlate with the stupid people assumption.
I curse in anger and to illicit a laugh. People get far too serious about words and speech, and it's not affected my vocabulary since it's not a replacement for a more nuanced response. I just don't care about swearing and the rules society imposes on speech.