Sure, Articuno has Bad typing, and is moveset is not that great but I really just don't get it.
Articuno does have a 4x weakness to Stealth Rock
Articuno's poor defensive typing prevents it from being a fully defensive wall, and its average offenses make it too weak to be a fully offensive sweeper.
Articuno competes with other Ice-types in the tier, namely Aurorus, Jynx, and Abomasnow, all of which are more versatile and stronger offensively.
Articuno sits in a slightly awkward Speed tier, leaving it outpaced by common threats like Kangaskhan, Primeape, and Dodrio.
...can be more easily pressured by strong wallbreakers.
Source
Hope I helped!