Because separatist Ukrainian identity/ideology is a recent invention (by the Austrian ruling Lvov area in XIX c). Lemkos were too far to the west and too stubborn to submit to this political manipulation.
"Lemkos were too far to the west and too stubborn to submit to this political manipulation."
Then why did they wind up in Muscovy churches? And why is Lemko most similar to Ukrainian?
And what is so recent about Ukraine - a culture that goes back to the very significant 10 century BC Tryptillian cities.
Ukraine in this sense certainly predates Poland.
"Lemkos were too far to the west and too stubborn to submit to this political manipulation."
This article documents the success of the Russian church in dissolving the cultural identity of a significant segment of Ukrainians. The Russian Orthodox church has successfully inflicted these people with cutural amnesia so that they have no idea of their backgroud.
Fortunately, Ukrainian groups are successfully resurecting the collective memory of a near extinct European culture .
http://64.233.161.104/search?q=cache:J5xl6h6zy7kJ:www.lemko.org/lemko/vatra/2005VatraUS.pdf+SUM+lemko+vatra&hl=en&ie=UTF-8