I live in Wisconsin and at the bars most players believe that it is illegal to shoot and score from the 5 man. Thanks to this site, I now know that it is legal.
Where does this misconception come from?
Lots of games have bizarre "bar rules" that are different from the real rules. Go into most bars to play pool and people will have a number of odd rules, including things like "on fouls you have to put the cue ball behind the head string and shoot at a ball in front of it" instead of normal "ball in hand anywhere, shoot at anything"; you'll have people saying "you have to call combinations/banks/caroms/etc" instead of the standard call-pocket or any legal shot rules (for 8-ball/9-ball respectively), etc.
Common bar rules for foosball that are not real include:
1. 5-bar shots don't count (though usually if you stuff their goalie from the 5-bar that's allowed)
2. The ball gets tossed randomly into the table instead of being served by one team or the other
3. Shots with the goalie rod count for 2 points
4. "Clean shots" only, if you hit their man or a bank it doesn't count
I have no idea how they got popular, just like I have no idea how the "fouls in the kitchen" pool thing became normal despite making it so that fouling can actually be to your benefit.
Even though it's legal do you consider it unethical?
No. In doubles, it's usually a bad choice but it's not unethical; I'm happy if my opponent takes to 5-bar shots because it means I'm almost certainly going to win. In singles, transition is a huge part of the game and the top pros will gladly shoot off the 5-rod if the opponent isn't guarding it--if you didn't, they could get a big advantage by playing left-hand on the 5-rod, right on the 3-rod (doubles positioning) in singles.
I think I have a great 5 man shot and mix it in every once in a while. Is this ok both from an ethical standpoint (considering it's kind of frowned upon at the places that I play) and from a strategic standpoint?
Do any top players shoot from the 5 man or is it considered a disadvantage?
In doubles, it's usually low percentage, but if it's open they'll certainly take it. All the top players (Billy Pappas, Frederico Collignon, Tony Spredeman, etc) will use 5-bar shots extensively in singles--normally not as the primary option, but worked into the rest of their game and disguised to complement their passing series. And they'll take them in a heartbeat if there's an obvious opening.
Legal and ethical.