Although they were ambitious, the Greeks post-1824 were never a numerous people, and their reach usually exceeded their grasp.
The Greek language, for one thing, historically had been slow to spread beyond ethnic Greeks themselves outside of Anatolia, and in Anatolia itself Turkish immigrants to Anatolia kept their own language and eventually largely displaced Greek-speakers. The Byzantine empire failed to leave multiple sucessor states speaking Greek derivations the way the older Latin Roman empire did in Spain, France, Italy, etc.
Part of the problem is perhaps that a sense of the importance of being "Greek" as an ethnos was to some extent lost during the Byzantine period: the subjects of the Emperor in Constantinople thought of themselves as Romans and Orthodox Christians who simply happened to speak Greek: "Hellenes" were ancient pagans. Modern Greek nationalism with its identification with the Glory That Was is largely a 19th century creation. Why bother to "Grecify" subject peoples, as long as they obeyed the Emperor and followed the correct form of Christianity?
(I may be speaking out of my sphincter here: any Byzantine experts please correct me if I err)
So how do we increase the numbers of Greeks? We can of course do a lot if we have PODs going back to Justinian's time, but lets make this harder - let's try with PODs after the Ottoman conquest. How do we get a larger number of self-identified Greeks today in 2010, with post-1453 PODs?
Bruce