I understand this. I actually do. Russia doesn't want "enemy" weapons on its border.
However, before this event, the situation between NATO and Russia is nowhere as tense as it was during the times of NATO and the Soviet Union. Maybe Russia thought its "interests" were at risk (even while Europe was hungrily sucking up its oil and natural gas), but they were not at the brink of war or invasion by NATO.
Furthermore, "but muh Cuban Missile Crisis/Monroe Doctrine interventionism" is whataboutism. If it was wrong for America to saber-rattle against the Soviet Union and support rebel groups and movements to overthrow pro-Soviet/Russian governments, why does that mean it's acceptable for Russia to launch an all-out war?
As for the whole "NATO supports (((((((globohomo))))) so Russia is based" edgelordery floating around this thread, as much as I might not enjoy a gay pride parade going down the main street of my city, I'd still rather have that than a parade of APVs from a belligerent foreign nation.