Does Nasus REALLY need to be a tank AND a carry?

Before you regard this as just another Nasus salt thread and comment "deny him and gg", please considering the following.

OTHER PERMASCALING CHAMPIONS ABILITIES:

(RIP): Q: Baleful Strike - Deals damage, and if it kills a unit, grants a small amount of AP. Also allows for his kills to give him somewhat more AP.

: W: Soul Furnace: A shield that also gives Sion a small amount of permanent bonus health whenever he kills a unit.

NASUS'S PERMASCALING ABILITY:

: Q: Siphoning Strike: Causes Nasus' next basic attack to deal bonus damage equal to three bonus damage per minion killed with the ability and six bonus damage for each large monster killed with the ability.

WHAT THIS MEANS TO OTHER PERMASCALING CHAMPIONS:

: Veigar's Baleful Strike allows him to scale high amounts of AP into the late game based on however many kills and minions he has taken. However, because this AP alone is not enough to keep him a threat, he still has to build AP items to have relevant damage and maximize his cheese potential. He sacrifices tankiness and survivability for high damage and gimping potential - this is, in my opinion, quite balanced.

: Sion's Soul Furnace allows him to scale high amounts of health into the late game based on however many minions and monsters he has taken. However, because the ability does not provide him enough damage to fulfill his intended role as a tank, Sion cannot afford to build full damage. He sacrifices high damage outputs for tankiness and survivaility - this is, in my opinion, quite balanced.

WHAT THIS MEANS TO NASUS:

: Nasus' Siphoning Strike allows him to scale high amounts of damage into the late game based on however many minions and monsters he has taken. The ability actually DOES provide him with all the damage that he needs, and allows him to build full tank and still remain a massive threat to enemies and, more importantly, enemy structures, which he can decimate with enough stacks. His ultimate and passive (20% lifesteal are you joking) allow for him to scale quite well with most tank items, and his W and E allow for him to have enough utility to not even need his Q's damage to be useful. This is, in my opinion, not very balanced at all.

BUT HEY, JUST DENY NASUS, RIGHT?

Well, sure, you can try that. And I guarantee you it'll work great, until you inevitably have to back, and upon returning to lane, find that now has 30 stacks and a Frozen Heart, and can now snowball all he wants.

More importantly though, why do we have to deny constantly, when we never have to deny and ? Both of these champions can be left alone to free farm all game, and unless they get kills, will not become massive threats. It just doesn't make sense that Nasus is litterally the only champion in the game that HAS to be denied, or else GG.

SO WHAT CAN WE DO TO CHANGE THIS?

Considering the real problem here is that can build full tank and still output massive damage, I think it would be reasonable to either:

1. Nerf Nasus' strengths as a tank (change his passive, lower ult health, lower utility, etc.)
2. Nerf Nasus' strengths as a carry (lower number of stacks gained on unit kill, remove ability to cast Q on turret, etc.)

CONCLUSION:

Personally, whenever I play top lane and see someone has picked into me, I know that the upcoming game is going to be far more stress than it will be actual fun. It seems highly unreasonable that a champion can be such an unkillable tank while also doing such high damage and having a more-than-reasonable amount of sustain and utility.