There are a couple of things in this discussion that puzzle me.
The first is the idea that people who schedule breakfasts before park opening are paying for the privilege of some advantage at rope drop. As far as I know, the people who eat at 8 AM are paying the same as those with reservations at 9 or later. So, IMHO, any advantages, like a quick spin or two on 7DMT, should be seen as a special perk, not an entitlement.
The second thing is the comments that some people have made that, without the perk of a free ride or two on 7DMT, nobody would make reservations for breakfast before park opening. Maybe it's just us, but a couple of years ago (before 7DMT opened) one of my adult daughters decided that she wanted to celebrate her birthday with breakfast at CRT, something we had never done before. We made the reservation for 8 AM on a day with a 9 AM opening, not because we thought we would get some special head start at rope drop, but because we didn't want to forfeit the ability to take advantage of short lines when the park opened.
It has to be understood that this issue is purely a result of the current popularity of 7DMT and the change in RD procedure it produced. Before, when the ropes at the front of the park were dropped, guests streamed into the park, but were usually held at secondary ropes leading to the various lands and the most popular attractions. A few minutes later, CM's led guests toward things like Space Mountain, BTMRR, etc.
When we had our CRT breakfast, we finished our breakfast before 9 and were held in the area around the castle. We were held there even when they let people in the front gates, and it was fun seeing the crowd streaming down Main Street. Then they let us proceed to the secondary ropes, where we seamlessly joined in with the other guests. So, the breakfast got us neither an advantage or a disadvantage relative to other early guests. When they dropped the second ropes, we headed right to Space Mountain just like we would have if we had entered with the main crowd.
With the new entry procedure and controlled stampede to 7DMT, it is much more difficult to execute a seamless merger of the small group of early ADR guests with the horde of others. Allowing those ADR guests a quick ride on 7DMT before the horde arrives seems like a sensible way to handle this.
All this having been said, I agree that Disney should try to have its opening procedure be as consistent as possible so that guests who care and plan have a good idea of what to expect. It sounds like what happened on the day the OP visited is clearly the exception and not the general rule. Maybe 7DMT wasn't quite ready to open early that day.
The bottom line on this for me is that I don't see me scheduling a reservation for a meal I don't really want just for a benefit that I didn't pay for and might or might not get. If I have an expectation of some special perk, and it doesn't pan out, I will swallow my disappointment and move on.