I think "cragildart" is correct. Firstly I find it amazing how many people seem to be insulted and even have to write posts in a disrespectful manor as though some sort of defense mechanism for being guilty of something. Basically saying - "this is what I do and if you think its questionable, well then F.U and your an a-hole.".....That attitude in itself is part of the etiquette problem to begin with.
But the fact that some people take such a drastic personal defense in itself perhaps does imply just may be there is some wrong with this after all.
Singles line was not intended to give singles some sort of privilege over the rest. And it was not intended with the thought of giving groups an option to split up into singles. Its simply a means of forming a line for singles and to assist in filling chairs. But unfortunately many times and too often is not what it does. I'll offer more on that in a minute. But....Skiing/boarding as a group together and getting in the singles line and re-grouping at the top and going down again as a group and again using the singles line and repeating this no matter how you slice it, is not imo good etiquette, Its not what the intention of the singles line was for. That wasn't the mindset which caused the idea of a singles line. Its not illegal but what we are talking about here is not legalities but is simply about morals and principals. Many of the very same groups selfishly doing this are often the same ones who also have all their stuff clogging up a huge table or two in the lodge or have a squatter holding 8 seats while others are trying to squeeze somewhere to eat. You all know who you are. Here again will probably cause some aggressive defensive responses. And fwiw I do tend to find many more snowboarder groups to split and use the singles line than I do skiers. Mostly because they tend to be younger on average and along with being younger comes higher percentage of those who lack etiquettes, and common courtesies so it sort of comes with the territory. 6,7,8,9,10 boarders all together and all sailing in the singles line and then all waiting a top to repeat the whole thing again.
The problem with the singles line being filled with split groups is that what happens too often is this. With all the true singles in the single line there are none in the regular lines. And what often happens is that a single line also being filled with groups can build up and the liftees then start to call a group of singles together anyway. Sometimes two and at times even more just to get the single line moving. This happens quite often and is why it becomes unfair. All the well intended thought process for having a singles line gets abused and totally falls out of its own purpose. It becomes more of a line cutting technique vs what it was intended for. The more and more groups who use the singles line to their own advantage makes the problem worse and worse. If all singles was simply in the regular lines due to no singles line on a crowded day a good lift attendant would have all chairs (with minimal exception) filled regardless. And I do (as been mentioned) get tired of seeing 2 boarders on a quad chair or 4 on a 6person chair especially when from the singles line. Bottom line imo is that groups using the singles line is only working towards hurting its intended purpose in the first place. Its abusive imo and makes something intended to be productive now counterproductive. Many of you who are all for using the singles line as a group also admit if everyone did it, it would no longer work. That in itself suggests that it was never the intent of the singles line and therefore not technically the proper thing to do.And you also know this and like it or not (and get insulted or not) you are playing your part in working it against its own cause.
If far too many keep doing it your going to be upset it no longer works but in reality your part of that self destruction because it was never the intended goal for it in the first place. So yes, I think in the end it is not good etiquette, but (like it or not) simply a selfish move. The reason it doesn't usually ever get to the point of being self destructive (yet) is because enough people still do maintain good etiquettes. This s the only reason it still works for you. If most had the same selfish motivations and disregard for the intended moral guidelines or unwritten rules than you would never gain any advantage by using the singles line because so would everyone else. So its indeed a away of taking advantage of the fact that there are still enough people who do follow intended guidelines with good etiquettes. Like it or not and admit it or not, people who are following the unwritten rules are being taking advantage of. That's why the whole thing has a question of etiquette.