I read the full thing, in fact, the rammus statement is in the second sentence. Which I'll admit I mis-sread, I thought you were saying you did a smart thing and picked rammus, instead of the enemy. Either way not a thing changes. With the way you're re-iterating your statements, I continue to stand by my previous point, but add that "Solo/Dynamic queue" players rarely pay any attention to other people's picks. Which yes, certainly can be an issue. None of them individually made a bad pick, but failing to adjust their picks based on the rest of the team was certainly an issue. Though those picks being marksman in particular I don't feel has anything to do with... anything. Your team stacked AD, it happens, and it got punished.
If you had Riven top, Zed mid, and a panth/J4 kill lane bot, you would have 0% of the marksmen, and the 100% of the same problems. I think you're completely misunderstanding the issue, and throwing the blame in the wrong direction.
Not to mention the part about "babysitting". Sounds like they didn't do so hot in lane, which again, being marksmen specifically didn't change anything. Would it have been better if you lost with a proper hybrid damage team? Because that happens too! Lanes get lost, games get lost. If you want to rant about people not adjusting their picks in champ select... sure... That's been a problem since... the very first queue.
I'm sure you've made picks before without thinking/caring if they're actually great for the team. Because you really want to play a certain champion, or you really feel comfortable on a certain champion, or you want a champion that does better in lane against what you saw picked, you think about those things instead of your teams comp.
Which honestly in all but the highest brackets has merit. The way league snowballs these days, if you win lane hard, you're a long way towards outright winning the game as long as there isn't an equal counterpart on the enemy team. Your team "comp" matters less and less as games get more and more snow-bally. Welcome to the new League of Legends, where strategy and teamwork is secondary to flashy moves and cool names for casters to say!