OP - rough situation, and understandably frustrated.
PP - People who are defending Disney on this because "its a new ride" or "Look at opening day for X ride" you are missing the point.
Yes Mine Train is "new" but its not opening day, but people are still trying to get their first rides in on it, all the return guests etc, so sure its still quite popular.
But here is the Rub, the issue the PP is having is the result of FP+, not a "New Ride". Before FP+, he could have just showed up at RD, walked over, pulled a FP, and come back at whatever time they got. Now sure that means a less planned out day, and there was no way to control what time he/she got, but they would have the FP, no question.
Now, they are shut out for 30 days, and the pool of FPs are gone before they even get in the park.
For no other ride was this true in the history of Disney, that 70% of the capacity could be booked 60 days before the park even opened. This isn't just "its a new ride" its "its a new ride with FP+" and there is a HUGE difference.
The OP is also correct in worrying about how this is going to play out for other attractions. Every new attraction is going to be like this ... its going to be "get on at 60 or good luck".
Now people can come in and post pictures about how THEY were able to get what they wanted under 60, but the Math of the capacity of these rides dictates that not everyone can, far from it, and this is far from the first story like this we have heard, its becoming a pretty regular thing here. Think about how regular it must be out in the real world of Disney vacations, at least here we know what we are doing for the most part, we know what to prioritize and when to get on etc .... had a student come to my last week and tell me I would be excited for her news ... they are going to WDW for 2 weeks in May !!! Awesome I said, where are you staying (fort wilderness), cool never stayed there but its right near wilderness lodge which I love. Have you booked your Fast Passes yet ??? Um ... fast what ?