Well, do you really understand how stats work? If you think any given pokémon can be raised to its species' max stats, then you don't know how stats work.
There are five components to a pokémon's stats. Two are species and level. These are obvious. A third is nature; your pokémon's Natures (such as Brave or Hasty) boost one stat by 10% and lower another by 10%, except for five natures that raise and lower the same stat and thus do nothing. I think most listings of "max stats" assume these neutral natures, but if the max stats you know of assume a boosting nature for each stat, well, that's obviously not possible on a single pokémon.
The other two factors are hidden values. First are Individual Values (IVs, also known as DVs for no real reason.) IVs represent inborn talent on the part of the pokémon, and they are what make one wild pokémon different from another of the same species, aside from natures. A pokémon has six IVs, one each for Hit Points, Attack, Defense, Special Attack, Special Defense and Speed. An IV can be any number between 0 and 31; the higher the IV, the better the stat will be. The difference is more noticable at higher levels. In your case, you might have been unlucky enough to catch pokémon with generally poor IVs; since there's no way to change a pokémon's IVs, the only solution is to catch different pokémon of the same species, raise them up to the same level and see how their stats compare.
The second hidden value is Effort Values, EVs. These represent the specific sort of training your pokémon have had. If you have a pokémon battle lots of speedy pokémon, for example, its Speed will develop faster than usual. Like IVs, there is an EV for each stat. Every time your pokémon earns EXP from a battle, it also earns EP, Effort Points that go toward building its EVs. The species (not the level) of your opponent determines the number and type of EP you earn. Also, the supplements HP Up, Protein, Iron, Calcium, Zinc and Carbos grant extra EP. If you want to make your pokémon the best it can be, you should be careful about how you build its EVs, because there are caps on how high they can go: each EV can go only as high as 255 (and, actually, the stat stops improving after 252,) and you can only collect 510 EP in all; that means you can max out only two stats on any one pokémon. If you're raising a pokémon with all physical attacks, and it winds up collecting a lot of Special Attack EP, that pokémon's lost a lot of its potential.