Some social projects are for special circumstances, like if a planet is under influence attack and needs to boost its resistance. But I agree that some social projects need help, I never build them, as the bonuses they provide are far too small for the maintenance they require. Some I find out of line:
Galactic research center, 400 cost and 5 maintenance for 10% star influence and 45% research. But the huge maintenance cost forces you to reduce spending overall significantly thus greatly reducing the net +research benefit. I need to get some numbers on this to see if this building is actually worth it at all.
Info Net, 300 cost and 4 maintenance for 5% econ, 1% star influence (probably meant to be 10%), and 10% research. Not even close to worth it, even on a huge planet, under any circumstances I know of. Make it +25% research and +10% influence and then it would be worthy of consideration.
Medical Center, 100 cost and 2 maintenance for 5% morale, 5% research, and 5% ships. Just not worth the effort. Doubt I'd even build it for 1 maintenance, it needs to be more effective at -something-. Try +10% pop growth, +10% morale, +10% research, and +5% ships and it would look a lot more attractive for 2 maintenance.
Orbital Hospital, 200 cost and 3 maintenance for 10% morale, 5% star influence, and 5% research. Too much maintenance for what you get, 1 maintenance would be more in line with the benefits, 2 at most. I doubt I'd build it if it was 2 maintenance, to be honest.
Virtual Reality Center, 400 cost and 5 maintenance for +20% morale, way too much maintenance, totally out of line with the other +morale projects, should be about 2 maintenance.