I just don't think Russia joining NATO is an apparent slam dunk success. Maybe it would have been great, we can never know for sure, but I can understand the suspicion.
With what goal?
Nobody in Russia would've supported such an unthinkable war.
It took a coup in Kiev in 2014, burning people alive in Odessa, all the slogans 'Hang the Russians', dozens of streets named after Nazi collaborators, the war of the new Ukrainian government on the separatists in the East and eight years for people in Russia to start thinking that not all Ukrainians are brothers.
The tone struck by Vice Chancellor Sigmar Gabriel, head of the Social Democrats (SPD), contrasts with that of conservative Merkel who has pinned responsibility on Russia for exacerbating the crisis, which has soured ties between Russia and the West.
"Certainly, the European Union has also made mistakes, although this does not justify Russia's behavior," Gabriel told the German daily Rheinische Post.
"It was certainly not smart to create the impression in Ukraine that it had to decide between Russia and the EU," the Economy Minister added." [0]
[0] https://www.newsweek.com/german-official-says-it-was-wrong-m...
Nobody would be against, in the same way there isn't anyone against this unthinkable war now. Why are you on HN. Maybe you should go and try to denazify some other website instead?
Your own link says: "The treaty proposed equal limits for the two "groups of states-parties", the North Atlantic Treaty Organization (NATO) and the Warsaw Pact" and later "most former non-USSR Warsaw Treaty members subsequently joined NATO, followed later by the Baltic states and the states of the former Yugoslavia".
"CFE-II took into account the different geopolitical situation of the post-Cold War era by setting national instead of bloc-based limits on conventional armed forces. NATO members refused however to ratify the treaty..." [0] What a surprise.
[0] https://en.wikipedia.org/wiki/Treaty_on_Conventional_Armed_F...