I find this strange as it has been explained a lot of times that the reason they will not question him on the UK is because he not only may be arrested after the questioning, but he may need to do more questioning after one round is done. Basically, they need him in Sweden because anything can happens in the questioning. Also, although it has been done in the past (the questioning not in Sweden soil), it wasn't done to the accused but to people related with the case.
Also, did he really said that or are those quotations mark artistic license?
You, on the other hand, imply that countries around the world somehow have to send random people to Sweden, for no other reason than to save the Swedish prosecutors the effort of traveling there to ask questions. How silly.