There is a technical reason for the Greek letters, other than being a sign saying "go away, thickies". They are neutral, scientific-like labels for the questions. Since many of our questions contain numbers, letters, symbols, colours and other natural labelling systems, it makes sense to use a label that is impossible to confuse with an actual clue.
And, after many teams being tempted in the past, someone does have the guts to ask for the "squiggly one" later in the series.