Well it is probably inevitable that having written on this topic it would come up in a game. Actually similar hands came up twice yesterday. The first is an example of an even more common example than the one previously mentioned.
My team was winning 8-5 on my deal. Queen of Spades was dealt and after calling and discarding, I held:
Jack of Spades
Jack of Clubs
Queen of Spades
Ace of Hearts
King of Hearts
My opponents led a low heart which was trumped by my partner. My partner led back a low club, effectively finessing my two bowers. If I trumped with the queen, I ran the risk of my opponent overtrumping with a king or ace. I took trick with one of my bowers and led out the other bower, but my opponent on my left now had ace protected. She played off a low trump and eventually had stopper.
If I had gone alone, I would have take first trick wih the ace of hearts and run trump, taking four points.
Of course--and this is an important point--there are configurations for both of these hands that would allow them to march (take all 5 tricks as partners for two points) but not march alone. So one can say, "hey, hindsight is 20-20."
Euchre is a game of probability. My point with these two examples is not that going alone with eight points is the better play or always the right play, only that it is an acceptable play. There will be times when you choose a 65% play and it doesn't work, while in hindsight the riskier 50% play might have. That doesn't make it the wrong play. Also, don't forget to factor in who you are playing with and how well you know their tendencies.
Going alone with 8 points isn't always right, but there are legitimate reasons to do so with certain hands that have nothing to do with bad table manners.