This is probably the single greatest shortcoming of these games. They've got such wonderful polish and are really fantastic, but the amount of Pokémon you can access before the first few gyms is laughable.
The fact is, the early-game Pokémon of Black and White are all fine in their own right, but... there's so few of them. Patrat, Lillipup, Pidove, is all we really get before the first badge (excluding the starters/elemental monkeys). I do like Pidove/Unfezant's design, but it suffers from a messy movepool and less-than-average stats. I love Stoutland's design, but to give it Sand Rush is such a niche choice, virtually pointless in the story mode.
Here's what we get in the other regions before Gym 1:
Kanto: Pidgey, Rattata, NidoranM/F, Mankey, Spearow, Caterpie, Weedle, Pikachu
Johto: Pidgey, Rattata, Sentret, Hoothoot, Caterpie, Weedle, Ledyba/Spinarak, Geodude, Zubat, Bellsprout, Growlithe, Gastly, Mareep (technically Wooper and Slugma too)
Hoenn: Zigzagoon, Wurmple, Poochyena, Wingull, Taillow, Seedot/Nuzleaf, Surskit, Ralts, Nincada, Shroomish, Skitty, Geodude, Whismur, Slakoth, and the optional Makuhita.
Sinnoh: Shinx, Bidoof, Starly, Psyduck, Machop, Geodude, Ponyta, Zubat, Budew, Abra, Magikarp...
(All off the top of my head, might've missed one or two)
To go from those, to the 3 available in BW, is truly wild. It does affect the replayability a bit, because the early game is.. not a grind, but a bit of a bore.