You show your bias as a Turk. Ottoman rule in the Balkans was oppresive towards Christians, just like in Ottoman Armenia. Of course there was no need to stabilize the border there.
Russia was the most expansionist of the GP's around the 1900's - and most likely since Napoleon. They didnt want stable borders - they wanted to conquer, to expand. They tried in China, in Central Asia, in the Balkans and even in the Caucasus regions. Im in full agreement with Koprulu Mustafa Pasha in regards of the Russian intentions.