My point is somewhat nuanced so I'll try to explain it more clearly. When these types of polls come out, often the reaction is "Wow, <other side> is definitely crazy, how can they want this?" But when you get down to the details, I think you'll find that the envisioned "actual implementation" of how this would play out is not as different as people think.
Simple example that could at least explain some of the difference. Younger people and poorer people (and, it the US, there is a strong correlation between economic status and race) are much more likely to live in communal setups, e.g. dormatories and apartment buildings, compared to older and more affluent people. So it's possible one group is thinking about this more as "There are already cameras in our hallways, why not hook them up to stop abuse?" while the other group is thinking "You want to put cameras in my bedroom."
That is, any pollster knows you can give extremely different responses solely based on how you word the question. I'm arguing that you could likely word this question differently and you would see responses that didn't nearly differ as much.
More than that, though, I totally agree that "'to protect people' will absolutely be the reasoning used." But I think even then it's important to understand the real underlying fears people have, and then point out that there can be other solutions that are much less intrusive and open to abuse, rather than completely discounting those fears to begin with.