Anon, again, apples and oranges; kitnios is a minhag. Hotzaah is deoraysoh. And it wasn’t only rav moshe – it was tje vast majority of poskim in America who joined him.
Besides that, you’re cherry picking a handful of psakim which rav moshe made which were not accepted. Rav Moshe paskened the biggest shailos in the country and was, in the satmar rovs words, “mara d’asra of America” despite their disagreements. Most of his psakim became the common standard for American jewry. It’s disingenuous to quote a couple of psakim and make it as though they represent the bigger picture.