Not saying you are wrong but, these types of debates always remind me of a verse in the Don Henley song Garden of Allah
I prefer Twain. ""Figures often beguile me,"
My point wasn't really to argue the meaning of the phrase "even money" but just to point out that one success in eight is much better than 50/50 odds. Subscribers can normally expect an average of one success in five over the long run on items with a 20% chance to RE. But they need to remember also that this isn't a guarantee of one in EVERY five tries and that the system isn't broken if they see longer failure streaks than five.
Though even I admit to grumbling about it when I hit 30 fails in a row.