In any case, because the MB and Chazon Ish say not to rely on it doesn't mean that it has massive Halachic issues. There are way too many practicing Rabanim and gedoilim who used this Kula in practice. If you want to be machmir, be my guest, or figure out another way around it.
Not sure why you’re ignoring Rav Moshe here.
Either way for mainstream poskim in the non chassidesh communities here it is indeed a big issue, one of the many pitfalls of a citywide eiruv. They would not want their communities put in a situation where there would be widespread michshal of people thinking there is a kosher eiruv when in their opinion, indeed according to the pashtus ההלכה, there is not. Not sure why you think they aren’t entitled to their opinion on this.