If the rav felt his congregants were up to dressing differently perhaps he would speak to them about it. Perhaps he’s still working on kashrus, shabbos and taharas hamishpacha with many of these people and he’s willing to look the other way if they wear hawaiin shirts to shul. There are 612 other mitzvos besides tefilla. Unlike some people here, the Rav is not willing to write off his congregation for how they dress.
