They have similar language to nordic ones, Yes. But the place itself feels and looks totally as Baltic country and there is absolutly nothing wrong with it. (I've been in all 3)
I think the reason is that Estonia and Latvia used to be same country - Livonia but I might be wrong.
Estonian an Livonian are Finno-Ugric. They have a relation to Finnish (but in no way to Scandinavian languages) and Hungarian. This group ist vastly different from any other language in Europe including the Slavic languages. Moreover, Livonian is not to be considered as equivalent to Latvia - Latvian being the official language there.
I think the reason is that Estonia and Latvia used to be same country - Livonia but I might be wrong.