I never said there was context that justifies Hamas targeting civilians, but let me make this really simple for you: The way Israel treats Palestinians in Gaza makes violent uprising inevitable.
And no, I cannot blame the Palestinian civilians there for supporting Hamas. They've been living under generations of oppression. They vote for Hamas because as horrible an organisation as it is, they know Hamas has been fighting tooth and nail for their liberation from Israeli oppression. They have actually traded blows with Israel and continue to do so. When you're under that level of oppression, that's all that is needed to justify that level of support.