Most of the babies get Charm, where their fully evolved form does not.
Also, some of the "babies" can get passed moves that the fully evolved form can not (Budew can get passed Extrasensory while Roselia cannot, Happiny gets Last Resort while Chansey cannot)
And Pokémon's movelists get revised every gen; that they gave Charm to baby Pokémon as an exclusive move is a poor attempt at justifying their existence. They don't need to create more babies just to give Pokémon new moves, or else we'd have babies for everything that got Shell Smash, etc. in Gen V.
Nasty Plot was introduced in Gen IV anyhow, so believing Pichu was introduced for anything other than marketing is flat out naive.
I personally dislike them. Even if they add new moves. In my evolution project, I set up a formula to decide whether the standalone Pokemon get prevos or not...due to this formula, most do not. --- NNID - Aerontar. Steam - KingAerontar Currently Awaiting...SSBU, SSB3DS, Pokemon X, Pokemon Y and Watch Dogs.
Not all pokemon are meant for the same audience. The game has a huge following and there are people that don't play the game competitively and they judge and use pokemon on criteria other that their "stats". I'm not one of those people, but I respect that they exist and am glad that gamefreak is able to please them as well as those who enjoy the competitive scene.
Counter-argument: Wynaut. It gets Encore... which can then be used to round out Wobbuffet's arsenal of counter-based destruction. Safeguard, Encore, then Counter or Mirror Coat depending on what you Encored. Also, a list of moves baby Pokemon give their lines:
Pichu: Charm, Sweet Kiss, Nasty Plot, Uproar (only Pichu can get it from move tutor) Cleffa: Charm, Sweet Kiss, Copycat, Magical Leaf, Uproar (tutor exclusive), Sleep Talk (only DW Cleffa gets it) Igglybuff: Charm, Sweet Kiss, Copycat, Uproar (tutor exclusive), Helping Hand (DW exclusive) Tyrogue: Tackle, Helping Hand, Fake Out, Uproar (tutor exclusive) Smoochum: Sweet Kiss, Confusion, Sing, Lucky Chant, Copycat, Uproar (tutor exclusive), Skill Swap (DW exclusive) Elekid: Uproar (tutor exclusive), Magnet Rise (DW exclusive) Magby: Uproar (tutor exclusive), Heat Wave (DW exclusive) Azurill: Splash, Charm, Bubble, Slam, Uproar (tutor exclusive) Budew: Water Sport, Worry Seed, Uproar (tutor exclusive) Chingling: Last Resort, Entrainment Bonsly: Fake Tears, Uproar (tutor exclusive) Mime Jr.: Tickle, Uproar (tutor exclusive) Happiny: Charm, Copycat, Sweet Kiss, Uproar (tutor exclusive) Munchlax: Metronome, Odor Sleuth, Recycle, Screech, Stockpile, Swallow, Snatch, Last Resort, Uproar (tutor exclusive) Mantyke: None. How useless. --- For those of you starting topics about the PS4, there's a PS4 board: http://www.gamefaqs.com/boards/691087-playstation-4
Counter-argument: Wynaut. It gets Encore... which can then be used to round out Wobbuffet's arsenal of counter-based destruction. Safeguard, Encore, then Counter or Mirror Coat depending on what you Encored.
But why not just give Encore to Wob? --- http://i.imgur.com/piMWR.gif
As said, they can used well or badly. Elekid and such are good use, cleffa and such is bad use. Hopefully they steer away from the latter in the future. --- River Song: Well, I was off to this gay gypsy bar mitzvah for the disabled when I thought 'Gosh, the Third Reich's a bit rubbish, I think i'll kill the Fuhrer'