What concerns me is that people act like she doesn't have the right to write her opinion (it clearly is just her opinion; it was published to the opinion section), without her facing repercussion.
Tolerance only goes so far. You can have whatever opinion you want, but that doesn't mean you get to escape the consequences of having views that people find objectionable.
You can certainly walk around town telling everyone they are stupid, but you shouldn't be surprised when everyone hates you afterward. "It's just my opinion" is a weak excuse.
It's not an opinion, it's a conjecture. Opinions are emotional responses to facts, not arguments about their veracity.
Examples of opinions include:
The color red is beautiful.
I'm sad that sharks are being hunted.
I hate poor people.
None of the following are opinions:
This rose is red.
My landlord poisoned my dog.
Poor people do more drugs than rich people.
In particular, a statement is not an opinion simply because it is presented without evidence. It is only an opinion if it can't possess any in the first place.
You can certainly walk around town telling everyone they are stupid, but you shouldn't be surprised when everyone hates you afterward. "It's just my opinion" is a weak excuse.