For many people here who don't know this. The NES was treated the same. It didn't get great 3rd party support until the near ends of its life. Kinda've like the wii.
OT: I don't think all those points are the main reason its not respected. Those are just flaws that people try to point out all the time. I think its the fact that they were wrong. They thought this generation was going to be King Kong vs Godzilla. 2 huge monsters with nouthing but power killing each other. Than rodan comes in and beats them both. Kinda've hard to accept a underpowered monster killing 2 huge monsters