Meddler

Plenty of other classes also get 2AP per strength, most other stats interact differently with the various classes too - the value of +hit to those dual wielding for example or +def to warrior/paladin tanks as opposed to druids. Varying stat impact is how Blizzard have deliberately designed the game, the problem here is that a core 5 point talent is dependent on itemisation to carry out part of its intended role and that itemisation is, at various stages, significantly lacking.

Back on the original topic of Feral AP as a mechanic though I'd personally argue this is not necessarily a problem - as above, the impact of stats on the different classes varies quite wildly but what matters is the actual results produced at the end of the process. In this case that's the amount of dps being done which, at present, is generally considered to be pretty acceptable given the amount of utility provided by druids in other forms. As pointed out above should this change in future that would be grounds for a reassesment.

Sure, the feral weapon AP could be buffed up however that would either entail a small but general buff to druids or simply a rebalancing of druid combat mechanics shifting increased importance to the weapon slot (adding dps onto the weapon, removing net benefit across the board otherwise to keep the end outcome the same) which I don't personally see any particular reason to do.