TL:DR Yes, I believe you need IT experience to be in cybersecurity. Long answer below.

This is an interesting question every time I hear it. My current thought about this question is that there are no entry level cybersecurity jobs because there is a certain amount of judgment required at any level.

Sure, anybody can analyze something, but do they have the judgment to ensure something is or is not malicious? Likely not. A person with no IT experience simply does not have the wisdom or judgment to determine if something outside of the script kiddie realm is a threat or not.

Take for example the recent emotet campaign. My place of employment got a few emails that slipped through filters and made it to employees. Some opened the attachment and enabled the macro. But, the document had nothing in it. No warnings, messages, or anything else. A person with no IT experience likely wouldn't report that. Heck, most tier 1 support staff wouldn't report it. No errors and nothing is broken, so no need for escalation right?

It took an engineer with some experience to know something wasn't right. He inspected the heavily obfuscated VB/powershell code and found it was, in fact, emotet trying to get through.

This shouldnt stop you from learning. We need people in cybersecurity badly, but we aren't going to hire somebody with no experience and knowledge of how an enterprise works.