I believe in data to a certain extent. We all watched moneyball and we all saw how teams are now even using big data to field players and yes it works more in American sports with stats, but I still think you can't really use the systems to play in team footballs especially. I think the bookies already use these systems in a big way, hard for the individuals like us to take advantage, so it's still about finding good value based on data to a certain extent.
I agree in parts with you...
Much of what happens in the game due to the luck factor, but the statistics canot be overlooked.
A weaker lineup, a wrong formation, an injured player, everything contributes to a negative result, and betting without taking this into account can be a big mistake.
So, I believe that statistics help a lot to predict the probabilities and help us not to bet on an unlikely outcome, which can be 50% relevant in a decision. The other 50% are the personal criteria of each bettor.