Ever since his mana nerfs, Nautilus has not been able to clear 4 camps in a row without blue buff. If you are going to gut his shield so he can spam his e for aoe jungle camps, there needs to be either damage being done to those camps or some kind of mana refund so that he can actually use the ability.
Update: Thank you for all the upvote everyone. Hopefully Riot will see this and development a clear plan for Nautilus in the next season other than throwing buffs at his Q (?). Us Nautilus fans just want to see him groomed to be competitive at a role and have the tools to succeed at it instead of being at less than 1% play rate in support and top roles. Riot should lay out a clear plan for Nautilus.
Season 5 had Riot give us a plan for him by writing
"By being the cornerstone to both his offensive AND defensive ability, Titan's Wrath forces Nautilus into a playstyle that is very binary - break the shield and he's harmless, or suffer if you fail to do so. Shifting power into Riptide lets him clear faster and take more actions per teamfight, which are two key areas we thought were weighing him down."
In summary, his shield was gutted so that he could spam riptide on jungle camps to keep up with the new AOE heavy jungle. He can't do that anymore and his shield still stinks. The latest Nautilus "buffs" were to enhance his hook (q) being stronger, which was almost a fake buff to get people to consider him again.
He's never going to be a good top because his kit is too toxic to lane against so he will be nerfed if he becomes commonplace. He is never going to be a good support because everyone knows Nautilus support falls off because he can't tank up like jungle (ha) and top Nautilus who get more gold. The easiest fix would be to give him monster damage buffs to his riptide. Ekko is already more viable than Nautilus in top and midlane yet he is being groomed for a third position which is mind boggling.