I don't think it's overall Disney dining not appreciating parties of 2 since my husband and I get everything we want. However, we we've found with Sci Fi is that it used to be all six of the people in the car all were gathered together and then taken to the car as a "group". Now, the two of us have been seated behind a family of four (in the same car) when they were halfway done with their meal. We've also been led to a car and seated in the front seat and then had people join us in the back after we had already ordered. We've had the same thing happen at the Biergarten where, in the past, all eight people at the table were led in together but now, you are seated wherever there is room.
And before someone says "Disney just wants to make more money", I think it's because more people are making ADRs in various party sizes so they need to be accommodated. There are tons of times available for dining so the system just matches up what can be matched up for that time frame.