Eak! This thread just gave me major anxiety for my upcoming trip! We are lifetime Disney-goers, and this is our first trip with our own littles, and I have never been negatively impacted by other families with their strollers (not saying I haven't been run over, I just assume it wasn't intentional... now if someone was yelling "Charge!" as they plowed me over, I maybe would be a bit more put-out)... My biggest anxiety around our trip is inconveniencing other guests, but my mantra has been that people will understand we are doing our best... I definitely thought it was acceptable to walk onto a monorail without folding up the stroller, and the plan was to keep the kiddos in the stroller for the ride. This definitely gave some insight that maybe that game plan wasn't as solid as I thought.
I think the fact alone that you're concerned about inconveniencing others indicates that you are probably not going to be a problem. The problem generally lies with those who are unable to see that anyone around them even exists and move through crowds as I'd they are the only people there. (Not saying that anyone here is like that, but at the parks, there are certainly many people like that.) Those people can be anyone- stroller pushers, those on ECVs and people who walk (again, not saying everyone is like that or pointing out anyone here on the boards). Some people do use strollers or ECVs as battering rams, but there are also plenty of people who walk in front of/ cut off strollers or ECVs (whether purposely or not) and it is often difficult to stop quickly. There just needs to be more understanding and consideration from all sides.
General toward everyone:
In regards to the monorail, everyone has a choice of whether to board or to wait for the next one. If you're about to board a crowded section with a stroller, be prepared for the CMs to POSSIBLY ask that you fold the stroller, and if they don't, be prepared to not have a seat or possibly have people packed in close to the stroller and your child. Or you can wait for the next one and possibly have much more room. Likewise, if someone (without a stroller) goes on to a crowded section with a stroller, expect that you may not have a seat. Again, you can wait for the next tram. It is exceedingly difficult to empty out and collapse a stroller once the monorail is packed full of people and there are clearly (as shown on this thread) several reasons people may choose not to collapse their stroller at all if they are not directed to by CMs. A folded stroller does still take up room, as does everything in it, and you must hold on to it, which sometimes isn't feasible if you are trying to hold onto little ones for their safety.
Everyone wants to get where they are going as quickly as possible. While I definitely appreciate the sentiment from some on this thread that things would run more smoothly if everyone showed a bit of courtesy for others, at the end of the day, every person is responsible for their own self. If it's crowded and all the seats are taken, don't expect someone else to move. If you have a stroller, expect that people will cram around it like sardines. One thing that worked for us is to try to put the front of the stroller near one of the sides or directly facing someone in our party that was sitting, that way there was less of a chance of having someone's butt in kiddo's face. If someone is leaning on your stroller, you can always ask them to stop, it's not their property. But also understand that sometimes someone might reflexively grab onto whatever is closest to them to keep their own balance from time to time and they might not be trying to be rude.
Point is, everyone has a choice of getting on a crowded monorail or waiting for the next one. It's that simple. Just like you shouldn't get on a packed bus and expect others to give you their seat, you shouldn't expect anyone already on the monorail ahead of you to change what works best for them to accommodate you.