Here is why smite "support" nunu is trolling:

It essentially makes the game a 4v5 because the adc gets completely zoned from exp and farm. You might think "won't it be a 4v4 because the enemy jungler won't get jungle farm?" Guess what, junglers aren't as reliant on gold as adcs, and they can get exp and gold from successful ganks and dives, espicially on the poor adc who is left alone in a 1v2. This is espicially true for tank junglers, who even if the worst happens to them, can still come back because they have innate utility and tankiness in their kit. What is a behind adc going to do? Zero. An adc who got zoned from exp and farm will be irrelevant unless the game goes to 60 minutes. He won't even scratch the enemy frontline. You might also think "the game doesn't revolve around adc you spoiled brat." Yeah, but that doesn't mean you let him starve to death because "the game doesn't revolve around adc."

tldr: Going double jungle instead of support is trolling and should be bannable.