I wouldn't just dismiss a stat out of hand like that. Aceves was undoubtedly more valuable than Lackey last year... not every stat gets it right every time.
Fangraphs weighs pitchers using FIP, which is a metric designed to eliminate luck from pitchers' performances. The past two seasons it has really emphasized the amount of "bad luck" that Lackey has had and has improved his value because of it.
Of course, by " bad luck" it really is capturing things similar to BABIP, which is a very useful stat but anyone who watched Lackey this year knows that his BABIP would probably be higher because there were many hard hit balls off of him.
In any case, Fangraphs is consistently saying that Lackey's results are worse than his performance/abilities should dictate. I would say the stat should be used depending on how much weight you give to this type of analysis. Fangraphs still said that Lackey was really bad according to FIP and WAR, it just seems that he had a better combination of other stats than the guys whose FIP was worse (K rates, walk rates, HR rates). He also pitched many more innings than Aceves, so he may have contributed more actual wins to his team because of that difference.
I think ORS laid out nicely why these types of metrics are useful. When they match your percieved list of player value--even if that list is mostly based on traditional stats--then you come to trust its validity. Then, when it spits out something unexpected, it can help you check your biases.
For instance, both sites do not list Lackey as the worst pitcher in the league.
With fangraphs I looked at FIP at a certain number of innings and (as discussed earlier) there were a few worse pitchers.
With B-R there are 3 pitchers over 100 IP who were worse/the same (Joel Pineiro, Fausto Carmona and Tim Wakefield). That more or less confirms my suspicion... especially having watched Wakefield. He was terrible for most of the year and his 'intangables' really hurt too.