How long have you got lol
I can't speak for "most agents" but top of the list for me is firstly the fact that I don't have to. Secondly, as you can see from kazedwards above, if Nicholas can't be a**ed to sell it why should the rest of us, and thirdly, as the vast majority of Nicholas customers decided it most wise to buy direct and didn't need an agent then, why feel the need to sit in our laps now?
I'm sure they gave exciting investment advice when they got people to buy, where are they now they want to sell? Nowhere! They don't even reply to their once valued customers!