There's a reason people love that episode, some ranking at as the best in the series, Fabio. Not every episode could match-up to that scene and the episode overall. If every episode was at that level you could argue that people watched Cowboy Bebop for the visuals, but like every TV series the series had some high points and many sverage.
I must admit, though, that I didn't recall Cowboy Bebop having that sort of animation. Like the artwork distracted me when I watched Akira, the shimmering did so when I watched Cowboy Bebop. If there's a serious flaw in the visuals, I focus on the negative.
As far as I know, the shimmering issue started with the R1 releases. Shimmering is caused not by the actual episodes but how they're put/encoded/whatever onto DVDs.
Do you have the KAA collection on your HDD? If so, KAA fix video issues as best they can, so the shimmering is still there but not as visible.