This is one of the most biased and fact-less posts I've read in a while.
Juggernauts like Nasus are supposed to be Tank killers and duelers. Darius and Garen both have True Damage and % Shred naturally build into their kits. Darius's is a passive he gets for free, meaning no mana costs, and Garen get's his in his spin and again he has no mana costs just cool downs. They excel at dueling and Assassins are not to counter them, rather ranged carries or fighters with true damage and mobility. Nasus in no way has comparable DPS to a ranged carry. He does not have 2.5 PS AS even with the Q CDR on his ult which last a paltry 15 seconds. All you have to do is not fight him in his ult, CC him and kite back.
Nasus will eventually scale there is no doubt about that. It is what he was designed to do. He excels in small skirmishes or splitting but fairs poorly vs heavy CC comps and team fight comps. A squishy will need 115 armor for him to have comparable shred on his E with the new change. Nasus and other juggernauts will always be good at killing anyone 1v1.
Nasus does not make Melee's useless and Cho Gath is whole other problem. He has % health shred on his E and it slows per each strike. He has a knock up that slows, a silence and atrue damage % missing health nuke ult. Nasus is single target while Cho essentially destroy an entire team solo being massively tanky with just his passive and feast and doing insane amounts of damage with just a ROA. His sustain is also much better than Nasus as he get mana back as well as health. These two champion are hardly comparable. Fiora, Darius, Garen, Jax, Olaf, Shen and many others scale just as well as Nasus and can easily duel him. A single executioners can invalidate a huge portion of Nasus's ability to resist anyone in the game.
Saying Nasus is a stat stick is irrelevant. Every champion is a stat stick if you are going to arbitrarily use that as an argument. They are either AD stat sticks, AP stat sticks or health and resistance stat sticks. This is not an argument it's a fact of every champion.
If Nasus was such an auto win why does he not have a better solo queue win rate? Why does he see no professional play? Your entire post is based on your emotional dislike for a champion and nothing to do with evidence or fact that is just purely anecdotal or opinion.