So which is it, are they being allowed freedom of movement into Israel to work with identification, or you don't want them in because they're terrorists who threaten to kill civilians?
All I've seen is that some people were allowed in and out, but it isn't exactly a porous border, identification requirements are strict, getting the necessary approval and documentation is difficult in a place without a functioning state. And you can't just make rules and distance yourself from the consequences of them just because people are unable to meet the requirements of those rules, you have to actually look at what the effect is.
Hamas doesn't exist in a vacuum though. Most people don't just wake up one day and think "hmm, terrorism sounds good to me today!" There's always going to be a minority of people who end up having extremist views and committing violence, but a functioning state is able to keep those people under control. The fact that Netanyahu has no motivation to make the situation better is directly what causes this situation where people help Hamas out of desperation. They can't wait for Israelis to get their act together and elect someone who is strongly motivated to make life better for Palestineans, they see that they have to live on the other side of a wall where only they have to deal with that level of poverty and violence on a regular basis and it's unfair. If you put yourself in their shoes you'd get it too. That's not a justification at all, it's just empathy for their situation.
I can also empathize with Israelis who want revenge. People in Israel expect safety and don't think of their country as a war-zone. It's easy to think of the problem as entirely one-sided when you don't have to deal with it, but it's just not the case.