Gen 2 was so poor as a generation that it created Gen wunners. These are the staple games in the series that had left such a bad taste in previous Pokemon fan's mouth that they were unable to move on from Kanto.
From there sparked all the common complaints of this particular group of people. It was in Gen 2 where over designed pokemon like Tyranitar and Blissey entered the fray. Gen 2 started to ruin fan favorites like Scyther and Onix with new uglier evolutions, Steelix and Scizor are quite abominable and only serve to introduce the Steel type onto already popular pokemon.
It was in Gen 2 where useless pokemon really took the lime light. Cleffa and Igglybuff serve next to no purpose other than being dex filler. Among them singular stage pokemon were rampant and considered quite weak, Girafarig, Corsola Dunsparce are remembered as among some of the weakest mons. Gen 2 also boasts having introduced Unown, and even the pokemon that holds the lowest BST of all, Sunkern.
Gen 2's dex issues don't stop there. It was in Gen 2 where the true oversaturation of legendaries began. Generation 1 had 151 pokemon, of those only 5 were true legendaries. In generation 2 of Pokemon we received 100 new pokemon but 6 new legendaries, far skewing the the number of legends to none.
Gen 2 truly was the beginning and strongest proponent of the divide in Pokemon fans. Later gens just remind us of where Gamefreak started to go wrong.