For whatever reason, this problem is most endemic in League of Legends (or at least feels that way due to the larger fanbase), but applies to every other game as well.
Making a prediction is incredibly easy. It requires zero knowledge or argumentation. All you need to do is say, “I think X team will win.” You don’t need to have a good reason. Hell, most people use terrible reasons such as, “I like that team.”
A lot of people even use their predictions more as a way to show their support with statements like “It’s my home team.” That’s all fair. It’s a fun thing to do and an easy way to engage in any game or match.
The problem I have is when these people get angry when their opinion isn’t taken seriously by analysts. But ask yourself, why should that type of opinion be given weight? This applies to both experts and the normal fan.
If all you’ve said is which team will win without any logic behind it, I can’t even give the bare minimum of credit even if you turn out to be right. Whereas if you write out an entire argument as to why a team will win, how they win, under what conditions they win, in my eyes you get the most amount of credit even when the prediction is completely false.
This is because even though the second person was wrong, they gave sound reasoning and an entire system that gives great background which you can then compare to what actually happened. This creates a very easy to follow narrative and most importantly to me, people can look back years from now and still understand the historical context of said matchup.