Golfer – “Live and let live” is an appropriate motto in certain cases. This case is one of them. They have a certain Minhag that has a basis and Rabbinical backing. It is none of your business.
The comparison to the Maccabees and Hellenists is completely inaccurate:
1. The Hellenists weren’t just “living and let living”. They were copying.
2. The Hellenists were oiver on clear-cut issurim.
3. The Maccabees told the Yidden to fight the Yevanim (and maybe the Helenists? I have to brush up on my Chanuka history). They were allowed and supposed to do this because the Gedolim of their time told them to.
There are times when we are supposed to give mussar. This is not one of them. And even if there were a chiyuv to give mussar, it would have to be given to the people doing it. You are not allowed to speak badly about one person to another. That is completely assur.
They have Rabbinal backing. This is their Minhag. Leave them alone. Our obligation is to judge favorably.
So, yes, in this case, “live and let live” is the right attitude.