I think it all boils down to an image problem in the US! As stated and noted by others, the brand has suffered in the US and IMHO if a hotel decides to spend money on a renovation they will get a better ROI by switching to another flag instead of spending the money on the renovation and staying with Radisson. (prime example the Radisson Blu in Philly which changed shortly after the reno.) Carlson tried to fight against this by putting the newly renovated hotels under the Radisson BLU banner in the US but that isn't working as there are not enough Blu hotels in the US to change the overall perception that travelers have of the Radisson brand in the US. IMHO the only way they are going to change consumers perceptions and make the Radisson Blu brand known in the US for quality is if they convince developers to open new hotels or renovate existing properties. Overall I think this is an impossible task. How to combat this? Renovate or open new Blu's in the US that are corporate owned and build up the brand so it is known for quality and hopefully won't be thrown in the "Radisson's are crappy hotels" bucket.
IMHO blaming the loyalty program for the brands problems is a logic you might see on FT but I personally think it is off base.