about that "Language should not be used to segregate and isolate groups,"
many russians refuse to learn Estonian and no one really knows why, most of the older (30+) russians and about a third of the younger generation are like that
on the other hand i do have many russian friends who speak perfect estonian and we have mandatory russian classes from the 4th grade until graduation in many schools, everything available in Estonian is also available in Russian and its impossible to get a job in places like stores and catering without being fluent in Estonian, Russian and English
the only thing is that unlike Estonian, Russian isnt an official language