Wall-E is bad science fiction

I should go ahead and write this down before I try searching about it on google, because I'm pretty sure that somebody else has already written something very similar.

I realize that Wall-E is intended for kids. I don't care. It doesn't work. I don't even care about the political agenda they are trying to push. Go ahead and push it, but at least make a few details plausible.

Even if it is possible for the earth to become that polluted and devastated, at least give some reason on how that could have happened. I just can't believe that people would be able to create that much waste without realizing that there was a problem and doing something about it. In addition, it seemed that most of the garbage was some form of metal. It would probably be easier to melt it down and reuse it than it would be to mine fresh ore out of the earth.

How could a seed have possibly sprouted on an earth that had been barren for 700 years? Where did it come from? If by some miracle a seed had been able to survive and still be viable after 700 years of crop withering weather, how could it have started growing? I didn't see any water, and it didn't get any sun--it was growing on the inside of a refrigerator.

The people kept having children for 700 years, even though they didn't seem to ever talk to each other in person or ever touch each other. The only thing that I can think of is that the robots harvest the seeds and grow the babies in tubes somewhere.

When the people (with major bone density loss) return to earth, they are able to walk with no problems, even though they have never walked in their lives. They never even walked in space. They were completely helpless if they ever even fell out of their chairs.

On earth, the plant was re-planted. Somehow, this plant, which was discovered on earth, was able to turn into millions of plants. It was able to cover the entire earth. Not only was it able to cover the entire earth, it was able to grow an endless variety of plants. I also saw, during the credits, birds, animals, and fish. This was not some remnant of earth life that somehow survived the 700 lifeless years. The flora and fauna came from nowhere.

I take umbrage. Please, please, if you are going to make science fiction movies, at least make them a tiny bit plausible.