1. As I said before, KLM can do anything it wants to do for it's elites on it's own metal. But if NW allowed this for FD/FB elites on NW metal it still afects ability of those on higher fares to upgrade to WBC if those seats have been snappede up by lower fare FD/FB elites.
2. Allowing people on cheaper fares to upgrade to WBC on a standby basis is a good idea from the travellers' perspective. If this were to happen, there would be many people congregating for upgrades on standby basis at the gate, thereby creating confusion as well as aggravation for gate agents and dispointment for the traverls unable to score a standby upgrade, not to mention the fact that it does, in way, lowers the perceived value of what the airline considers to be a premium product. OP-Up hopefuls will create the same problem too. OP-ups give airline a tool that they can use at their dscretion without having to contend with numerous standby upgrade hopefuls. As the phrase suggests Op-Up is done as a matter of operational convenience and our miles, which maybe valuable to us, are not money to the airline.
3. What is your idea of an expensive fare? Is B expensive for you? For NW it is still a dsicounted economy fare. Allowing a B fare to upgrade at the time of booking, which can be done upto a year in advance, diminishes the number of WPC fares the airline can sell at much higher business class fares. Why would the airline want to do that? Upgrades to WBC are awards and are capacity controlled just as award tickets.