I think as an outsider you are completely missing the point: if Estonians ever wanted to give the Estonian citizenship to the residents who are unwilling to learn the official language of the country, they would have already done that.
Because by giving somebody a citizenship, you give them the right to vote. And who would the Russian speakers vote for, if they don't speak any Estonian? Pro-Russian parties and politicians.
These people were never born in Estonia, they were born in the USSR.
These people never spoke Estonian, and never tried to speak.
Nobody ever asked them to stay in Estonia and to pay taxes in Estonia.
They are always welcome to leave, if they don't want to fully integrate into the Estonian society by learning the official language of the country.
Fundamentally, the ethnic Estonians don't owe anything to the descendants of their occupiers.