Why have some of Ash's old Pokémon that he currently owns never fully evolved?

[thomaswiencek]

All Ash's old Pokémon from the Kalos region capable of evolving that he still currently owns, but has kept at Professor Oak's Laboratory have already fully evolved. However, other than Bulbasaur, the one that has fought and managed to resist its evolution, some of Ash's old Pokémon from the Kanto, Johto, Hoenn, Sinnoh and Unova regions capable of evolving that he still currently owns, but has kept at Professor Oak's Laboratory, but that had never fully evolved include Squirtle, Bayleef, Quilava, Totodile, Corphish, Buizel, Gible, Oshawott, Pignite, Snivy, Scraggy, Palpitoad and Boldore. So, does anyone knows why you guys think that they've never fully evolved?

 

[Playerking]

Well I've mentioned this theory before on another forum and it seems a bit weird to some people, but I think it's because Professor Oak's Laboratory is the equivalent of a player's PC Box in the games. And you're Pokemon don't evolve whilst in the PC Box. Sure, Pokemon not being allowed to evolve in a specific place seems a bit weird, but considering all the strange things Pokemon can do and the fact that some Pokemon can evolve by being in a specific place also seems weird where you compare the Pokemon world to the real world.

 

[MarshiyanMisutaa]

Evolved pokemon have a tendency of losing their original personality and cutesy appeal, which makes it impractical for them to evolve.

 

[Rajas20]

Then you have to also consider that Ash in general never pushes any Pokemon to evolve, they always to out of necessity to protect Ash or help him. While at the lab neither is necessary so they wont. While it would be amazing if he had Typhlosion, Meganium, Feraligatr and Venasaur among others, I also believe this is done to also show Ash doesn't regard evolution as strength but the effort put forward. Also as said above, for kawaii appeal.

 

[hhhhdmt]

Its partially because the writers don't want the pokemon to lose their cute appeal as martianmister mentioned.

Its also partially because Ash has not trained some of them enough. Gible, for example, could have and probably would have evolved had Ash taken him to Unova and trained him there.

Sure, some very experienced pokemon like Squirtle and Bulbasaur (among others) have not evolved, probably because they don't want to. But others simply haven't gotten enough training.

Personally i do not want to see some of his older pokemon evolve but i would be happy if some others did. I would not want to see Squirtle, Bulbasaur and Corpish evolve even though i like their evolved forms. I just prefer them the way they are. They have been in their orignal forms for so long that i just wouldn't like if they were to evolve.

On the other hand, i would be thrilled if Gible, Quilava, Buizel etc did evolve.

 

[Cookies and Creme]

None of Ash's Pokemon do actual battles at Oak's lab as far as I know, and even if they do (eg Pokemon Chronicles) then I doubt it's enough for them to evolve/want to evolve

 

[Silktree]

Surely the real problem is that Ash doesn't use them anymore.

 

[KyseL]

Evolving Ash's Pokémon off screen is generally a bad idea in my opinion, you'd need exposition for it to make sense and adding even more exposition isn't good for the anime.