@old man
chukas hagoyim is not a “feeble argument” it is a topic of discussion in the shulchan aruch, among many rishonim, and is a topic of discussion in gemarah avoda zarah and a couple of other gemaras I can’t recall off hand. I believe there is a rashi that mentions darchei emori in chumash in relevance to going to the amphitheaters – although rashi himself would not hold that sports nowadays is an issue and the issue there was that they served a”z. It is mentioned in many modern day shu”t as well. If I wasn’t working right now I would compile a list of mareh mkomos for you on the subject. It is not a simple issue at all.
As an aside the point is not just intermingling – it is also following non-jewish trends for example wearing red. I believe chassidim don’t wear ties for the same reason. Ditto with the whole celebrating thanksgiving issue.