If I understand you correctly you are saying why it has to be that way?
In that post, yes.
Everything that goes in or out is controlled. Israel controls the water, electricity and everything else.
1) Egypt has a crossing into as well which is somehow conveniently ignored.
2) Hamas is the governing body and they have the responsibility to provide for their citizens. Palestinians receive infinitely more international aid than any other refugees. The fact the citizens have not seen a fraction of it is because Hamas steals it.
3) I forget the exact number, but Israel is responsible for something like 9% of Gaza's water.
4) There are some areas in Gaza that look modern, are well-built, and dare I say, even luxurious. That is where Hamas leadership lives. They could have built more throughout Gaza, but it is in their interests to keep Gaza looking as slummy and prison-like as possible.
5) Israel left quite a bit of infrastructure in Gaza when it left in 2005 which could have been used to build self-sustaining resources for the strip. Guess what became of them.
6) Every nation is entitled to open or close its borders at its own will. (Every time Israel opens the border such as by expanding Israeli work permits, they get rewarded with more terror attacks)
Now ask yourself why neither Gaza nor the West Bank was called "occupied" between 1948 and 1967.