Feif:
You are correct that there was opposition to Chasidus and the Rambam etc. long ago, and that therefore opposition in and of itself does not prove someone is wrong. But you also cannot use the fact that the Rambam had opposition to negate charges against MO, because the Conservative and Reform etc. can say the same thing: Maybe in 100 years everyone will agree that Reform is right, like they agree that the Rambam was right?
So now my question to you is, how do you know if the opposition to MO is like the opposition to the Rambam, or like opposition to Zionism or Reform? Isn’t it true that although there has been mistaken opposition in the past, there has also been legitimate opposition as well, and therefore, the most you can say is “I dont know if I am right or wrong. The Rambam had opposition but so did Reform. I do not know if I am like the Rambam or Reform.”