I haven't been to Shanghai, but the two rides in question don't seem all that similar at all to me....
"bike" seating versus sitting in an enclosed vehicle
launch coaster versus lift hill
outdoor portion versus completely inside
inside portion being lit up (including "racing" with the yellow bikes) versus sensory deprivation of being in (essentially) total darkness and not being able to know what to expect next.
And, of course, the entire themes aren't similar at all. One is going into a fictional computer realm and the other into outer space. Outside of the color blue, as someone previously mentioned, I'm befuddled how people view the experiences as all that similar at all.
As an aside, if we are talking about "purpose" -- wasn't Space Mountain supposed to be MK's equivalent to the Matterhorn? And yet DL got their own version of Space located not far away from the Swiss mountain -- are people bothered by that as well?