You are wrong. Again. DME can cause a retinal tear if the fluid pulls at the retina. As can a major bleed from new weak vessels growing due to retinopathy. The fact that you don't know this speaks volumes.
No, optometrists should not be responsible for deciding the severity of the retinal issues. They are extremely complex.
The OP is having blurred vision, which is central macula involvement right on the bullseye. Because of location, this means it is absolutely not possible for an optometrist to judge and make the call whether it is:
a) a very tiny, threshold size oedema that may self resolve
OR
b) something larger that definitely meets NICE guidance for immediate treatment to maximise chances of best visual outcomes
Perhaps you are simply incredibly naive rather than malicious, I don't know.
However it is very unethical of you to try to dissuade the OP from getting her eyes assessed by an ophthalmologist who is the best person to judge what treatment or timescales give the best chance at preserving vision.
You are utterly clueless I'm afraid.