There are two edges to the bias sword guys - the NRL grand final was great, you've got to be able to admit that.
Yes and No. I most certainly acknowledge that you are being 'fair and reasonable minded' about the bias, so well done.
Have not seen the grand final, and doubt I will, but I would be quite surprised if I found it was great. (I would certainly acknowledge if I DID find it great however)
On the face of it, I can see how that would come across as biased against (ie already 'deciding' I would not like it without having watched it) which is exactly what you are warning against.
The reason I feel quite secure that it is not plain old, uninformed bias is because I can state exactly the reasons why I do not like the game. The above illustration is one of them, constant interruption to the flow of the game. It just stops.every.tackle. Heck, you will be penalised if you strip the ball (or something along those lines). There is no competition for the ball, not at the tackle, the penalty (tap), the scrum.
To re-work those tackle numbers above another way, in 80 minutes (give or take, I know that game went into extra time) there is a STOP (tackle) every
7.881 seconds. That is not taking into account any penalties, scrums or kickoffs (restarts).
I might not like the game because of that, others might love it because/in spite of that. That is fine, each to their own.
BUT, it is not bias. Bias is exactly what HJ said above, a low score game in league is tough, uncompromising hard man defence but a low score game in rugby is inferior athletes incapable of attack. (loig is great and yawnion terrible)
Or, as you mentioned, the reverse bias from a rugby fan towards league.
It is the 'just because' that is a sign of bias. (just because league is better than union, or the reverse).
Knowing exactly why, and being able to articulate, why someone does not like a sport is not a sign of bias. Cherry picking, unequally applied standards (such as in HJs illustration earlier) are the demonstrations of bias.
And no amount of logic, or proof, will ever be able to make inroads on bias.