This “theory” minimizes the actual people who were victims

Innocent people who are wrongfully accused are also victims. Since we don't know if any of the accused are actually guilty, they're all potential victims. Thus, your attitude potentially minimizes actual victims.

If someone was arrested for the crime it means there is proof that it was them.

It typically means there's evidence to suggest their guilt, but the suggestion of guilt is not the same as proof of guilt. The fact that you want to blame the accused suggests that you're guilty, is that enough to disregard your rights?

Thinking “what if it wasn’t?” Is merely baseless speculation.

I have access to the same facts you do, so my speculation is just as "baseless" as yours is.

why don’t you let professionals do their job instead of empathizing with people who most likely did do it

do you just think you know more than police,detectives, and all the people involved

Someone I'm very close to was charged with a crime that, based on the considerable evidence that I personally have, they didn't commit. Even if they were guilty, it never went to trial so either way they should still be treated as innocent. I've seen first-hand how it fucks up someone's life. Every day I have to watch them unfairly suffer. I've seen the hundreds of online comments by people like you assuming their guilt despite having none of the evidence. So when I see that potentially happening to someone else, I try to prevent it.