Well, a line should be drawn I think. SOmetimes teams just don't have the talent to compete. Sometimes teams are just bigger, better, and stronger. Example. My 10th grade year we had a team that sucked for homecoming. My coach left the seniors till the fourth quarter and then put the scrubs (me lol) in while it was...34-0 I do believe. We won 46-6, which isn't all that bad haha. The opposing coach said he would remember it, and he did. My junior year we went to there place and they hadnt won a game. They put 50 on us, 50-30. Went for two point conversions every single time. Left his starters in the whole game, pretty bad considering we didn't do shit like that, we just left the seniors in till the fourth because of homecoming and all. Well, my senior year we had to go there again due to allignment re-adjusting, and we remembered it all too well. He took me and the rest of the starters out midway third when we had it well in hand, 36-0.
Now, I think if you run fake punts and stuff such as passing on first or second down when your up 30 or 40 points in the 4th quarter, its pretty pathetic. But if you are running dives, traps, counters, etc. and still scoring, it's the opposing team's duty to stop you. Especially if you have the second string or third in. The top team in our region just beat the fourth team 83-7 and people called for poor sportsmanship. Turned out it was 56-0 at halftime, and the starters came out midway through the third quarter or before because their coach said he had to leave them in longer to get into playoff shape. The team's starters haven't had to play any second half besides the first game and the game against us. In the first half the top team averaged two plays a drive...two plays. The team's first team D couldn't even stop the other's 8th and 9th graders. When something like that happens, it isn't poor sportsmanship. You aren't going to tell your scrubs not to try and score, that would just be stupid coaching wise, but you aren't going to run fake punts and be passing up 30-40 points, I don't think you should anyway.
Like I said, it all depends on the situation...but from what you described, I would call it bad sportsmanship and bad class. But then again, that's just coming from a soon to be coach.
Also, to throw in with VEL's point. A guy wrote in to a forum and commented on the situation. He said the way he would solve it is he told the offensive line if they did a good enough job, they could run the ball at the end of the game. So, when they would get up enough, he would flip the players (Skill players such as QB, RB, WR, etc. would play the line and the line would play their positions.) Most of the lineman were too slow to score and the QB's and skill players grew to appreciate the job the offensive line did. It was a winning situation for everybody, as the lineman blocked better to run the ball and the QB learned to appreciate them a HECK of a lot more, while the opposing team didn't get pissy about the score being run up.