At last Saturday's Tartan day event, I was the only man wearing a jacket (tweed, no waistcoat) and beside the pipe band, dancers and one or two others, the only man wearing a tie. Quite a few kilts with polo shirts, tee shirts, sneakers, etc. OTOH, many of the ladies were nicely dressed in sashes and/or tartan hostess skirts. I had no inclination to look down my nose at anyone there, regardless of their apparel choices. But I was quite comfortable being in traditional day wear appropriate to the venue and event. The few comments I received were all positive.
If you want to wear a kilt with casual, modern jeans outfits, that's fine with me. I may join you when the occasion calls for it. IMHO a Tartan Day celebration does not.