I think for this problem it really comes back to everyone's choice and also with what they want and what their purpose is involved, the logic is clear as you said if indeed they come only for entertainment then the question is why they watch while betting? isn't watching the game running just that entertaining enough? but yes as I said above that all this depends on their choice, maybe they will really be able to feel the pleasure if they watch while betting.
I just hope whoever it is will stay well and be able to maintain their bank balance by only putting the amount they can afford to be responsible for whatever the outcome is, especially losing.
Yes that's right, for people who choose to watch while betting I would give the same ideas and advice as you said, however if you do put money on the line then obviously this is a risky activity even though they basically want entertainment, because risk cannot always be avoided even if they are very optimistic in determining the team they choose, so one solution to minimize disappointment is to be strict with the limits they have set and by only using enough money as well as minimizing expectations on the final result.