Holy crap; you aren't kidding! I clicked on the link expecting something similar to a Bebop song, but it's almost the exact same music!!! Point made.
I still stand by my claim that the soundtrack is incredible; ripped off or not. And for me, it is an integral part of Cowboy Bebop. Changing the music for something more 'audience friendly' would drive the nail into the coffin of an already bad idea.
That would be a sensible approach, but for a franchise to be viable, the first film has to be a hit with audiences. The first episode of Bebop is one of my least favorite; it wasn't until I watched the episode introducing Ein (which ironically features the Imperial Drag/Seatbelts song) that I was hooked by the series. I guess if the producers made a first film based on the first 3 or 4 episodes of Bebop, it might have a chance of hooking some viewers...