The OP said "I'll side with the cynics" and then justified this by describing how they thought the device would operate — by detecting the plasmodium itself — and how they thought it was impossible.

The article, however, explains how the actual proposed means of operation is based on measuring actual symptoms of the illness — observable changes to the red blood cells — which is at least somewhat compatible with the mechanics of a pulse oximeter, and, therefore, not entirely unreasonable.

The tone was harsh not because of the cynicism, but because said cynicism was based on a concern that wouldn't even have been there if the OP had RTFA.

You keep saying Theranos. Are you of the opinion that we should treat all technical startup founders as probable criminals? I think where Theranos investors failed was when they confused media hype with due diligence. I'm perfectly ok to live in a society where imprudent investors get occasionally burned, if the hype can also put the spotlight on real, non-criminal founders that would have no chance otherwise.

This is far from getting funded, it's a technical concept and we have absolutely no ability or relevant information upon which to call it a fraud.

The above poster explicitly responded to one specific line of skepticism and is not telling them to give up all skepticism.

You are the only one trying to make this about "PC thinking".