Currently, we're forced to kill boars for an entire hour just to max out weapon skill. It would be much better if we could simply right-click a training dummy, go to the grocery store meanwhile, and come back to find it maxed. That would save time and make the process less frustrating and forced. Weapon skill, in general, is terrible game design and even Blizzard has admitted it.
A lot of things got axed in future expansions because they became more of an obstacle than a contribution. Imagine being level 100 and having to level a weapon skill.
They leave the weapon skill in Classic though because it's nostalgic and it does have more of a roleplay fit in the game. You get new weapons and level them up. Having a way to opt out of that would just make the whole mechanism null though.