I'm assuming that the average Palestinian feels persecuted, and is willing to support Hamas as the only group they see actively trying to do something about that, even if they don't love Hamas's methods. This support would evaporate quickly if they felt they were being treated like human beings.

If I were Palestinian and terrified for my family, I could see actively donating to and supporting Hamas, while also absolutely hating them and their methods, and longing for some other option.