we later learned that when russia withdrew from estonia they abandoned quite a few of their russian compatriots; russia had no money to feed and house these citizens in russia - so they just left them! the estonians don't like them because they say those people are not estonians, they are russians and russia should take them back. russia says: no thanks, we don't want you anymore. it's a cruel world!
yeh, you're right, it's a sad story, though somewhat more complicated than that: the majority of these Estonian (and Latvian) Russians were actually born
in the Baltics. They are children of the Soviet citizens that were directed there en masse in the fifties to seventies.
After the Soviet Union (re-)occupied the Baltic states in 1945, guerrilla warfare actually continued quite some time, particularly in the woodlands of Lithuania, where fighting continued till the early 50s and the last "forest fighters" were discovered in hiding in the sixties. The Baltic countries were a 'difficult' conquest for the Soviet Union because national awareness and unity was extremely high, bolstered by the interwar history of statehood, and the 1939-1941 Soviet occupation had traumatized the Baltic civilians to an extent that every citizen was a potential resistance fighter.
To pacify these countries, the Soviet Union used migration as a tool. Many thousands of Russians and other Slavs were sent to the Baltics in the fifties, or were persuaded to do so by bonuses and incentives.
Parallel to this, the Soviet mode of economic policy implied a great emphasis on the development of (heavy) industry. The Baltics were overwhelmingly agricultural countries with a great peasant rootedness to the land. Because of the resulting shortage of willing and qualified industry workers and a measure of distrust about the "reliability" of Baltic workers, workers were massively imported from Ukraine and Russia in the 60s and 70s.
The result: by 1991, Estonia had a 40% Slav minority, Latvia a 50% Slav "minority". Although migration had continued through the 80s, too, by then the overwhelming majority of these minority residents had lived in these republics all their life. They did mostly not, however, speak Estonian / Latvian, as that had never been encouraged - or necessary even: you have to realise that these Russians had been accorded a privileged position - they were the ones setting the standards upon the 'natives'.
There's the problem. You can see why resentment of these "immigrants" is extremely high among the Baltic peoples, but on the other hand, there was nowhere to send them "back" to anymore, either. After 1991, the Estonian and Latvian governments took a very formal line. Remember that the Soviet occupation was never recognized by the US; in the same vein these governments stated they were simply the continuation of the pre-1939 legal government, and everything in between was merely an illegal interlude. To those standards, everyone who had moved in during that interlude was de facto an illegal immigrant, and did not qualify for citizenship of the new state.
Understandable, perhaps, but also bizarre, as it left most of the Russian Balts de facto stateless. They could initially not claim Russian citizenship (never having lived there), and overwhelmingly didnt want to, either, not claiming it when it did become possible either. But they were not recognized as fellow-citizens by their compatriots either, and thus many held on to their Soviet passport, the passport of a state that didnt exist anymore. And imagine: a country with a 40%-minority without the right to vote.
Much has happened since. Some Russians have left, but not a whole lot, considering how much poorer Russia was and how few contacts or opportunities they had there. In a near-eternal wrangling with EU negotiators, Latvia and Estonia have made small step after small step to enable these Russians to get citizenship, and voting rights on at least a local level.
On the other hand, more and more of these Balt-slavs have learned the language, making it possible for them to pass the language test included in the citizenship application procedure. Also, they have started to identify themselves ever more with their country in what some social scientists term a new Baltic-Russian ethnic identity, one separate from both Russian proper and Estonian/Latvian. The hardline calls for Russia to reoccupy the Baltics or for the Russian-inhabited areas of Estonia to secede, that were making the headlines back in '91-93, have all but dissapeared. But this newly developed loyalty (not all new, btw, in the late 80s a significant group of Russians actually took part in the independence movements) has not yet been reciprocated much by the Balts, and the social chasms are still huge, as you have observed. Many are still left in the middle.