Well if you were concerned about which I could have told you that long ago, says right there in item.txt
We're just discussing why they made such a selection, they probably considered how the item fits, hence the scope only affects medium-sized humanoids, anyone else couldn't use it.

Pity the cyclops is not affected; if it were I might actually consider recruiting this overrated unit into my ranks.

If you feel like having them in your army, just open the file, go the the item in question, and edit the filter, adding whatever unit u may like. It's just a single player game, so if u like to have cyclops using the scope, just do it, everything will be alright :) only tool needed are 7zip, any text editor, 2 minutes of patience