well,
1.most melee champs get destroyed by him.
2.Hes almost impossible to safely gank, so youre SoL for help from the jungler.
3. Any champ who relies on "roaming" better learn to stay like 800 units from any bush, because theres always the chance he left when you did to set up the bush-of-death.
4.any all-in champ loses to him, since he generally rushes zhonyas, waits for you to dive him, uses its active, durdles while hes dying, gets the kill because his turrets don't turn off after he dies for like 5 seconds. gets more gold than you because youre worth the max since you just got a kill.
the donger is like the second best durdler in game, he doesn't care what you do, his turrets will kill you, hell just skip around donging and durdling until late game when his upgraded rockets one shot half the league roster.
also his success at low elos is because of the low-skill level of 99% of his gameplay, the durdling part
his "success" at higher ELOs is because they mastered the durdle eons ago and can now devote full time to aiming their upgraded rockets.