As far as the Greek Olgas are concerned, I am guessing but its popularity there may also have something to do with the relatively recent Queen Olga of Greece, who still has roads named after her in most Greek cities.
A very good observation and probably true. There is quite a lot about Queen Olga in the book I am presently reading about St. Nektarios but it is mostly negative and describes some of her meddling in various matters.
Does everyone else on this thread find the origins of words (not just names) as fascinating as I do? I also love researching various traditions and why people do some of the things they do.
For example, in the past, before all these new, wonderful, Italian tiles overwhelmed house builders here, flagstones were laid on paths and verandas, and porches. In the lent period just before Easter all the women would painstakingly paint(whitewash) the concrete spaces between the stones with limewash. Everything inside and outside the house had to be perfect for Christ's resurrection. A few years ago, while reading a book about the history of the Jews, I came across this exact same procedure. Good housewives would whitewash not only their houses but also the tiny spaces between their flagstones in preparation for one of their holy days.
Now of course, we have white concrete and don't need whitewash, although it was much healthier (when used on interior walls) because lime pretty much kills all the germs and bacteria it comes into contact with.