Reminder than even Volibear is a better top than Nautilus and Veigar a better support
Right now, Nautilus is objectively the worst or second worst champion in very single of his 3 roles, toplane, jungle and support, sporting laughable winrate (with only ryze having lower winrate than him) combined with extremely low pickrate (toplane 0,71% for 45% winrate). The only place he's doing well is in proplay, both because of better tanks often being picked and banned and because he still offer decent pick potential that a pro team can take advantage off. His extremely low mana regen tuning, lack of counterplay potential and terrible clear speed make both unsatisfying and unsuccessful in soloq however. There seem to be a real misconception about him in the community, so if you disagree, I would advise to please look at the stats and maybe fire off a gmae with him. In particular, try to compare him with tanks such as zac, maokai or sejuani in both laning phase, jungle clear and teamfight potential.
http://champion.gg/statistics/#?sortBy=general.overallPosition&order=descend&roleSort=Top http://champion.gg/statistics/#?sortBy=general.overallPosition&order=descend&roleSort=Support http://champion.gg/statistics/#?sortBy=general.overallPosition&order=descend&roleSort=Jungle