They are also betting and why shouldn't they publish results that would let them win even if that's not the correct result ?

One could argue that the masses would always return the correct score but imagine 50 people debating about sports, there are 50 opinions and the truth somewhere in between.

And therefore those people also called 'scouts' must be trained in order to accomplish the job.

Well, as there are comment threads on reddit and streaming websites, you just do some simple NLP.