The counter-argument is, of course, that someone who knows they can't fulfill all contractual clauses will try to check off the easy ones only - including the risible demand that M&Ms be sorted. The argument in the article is simply invalid, because it can be used to justify everything - the more unreasonable, the better!
Instead of such a ridiculous demand, they could have just picked a couple of random, but useful clauses from the contract (like the number of sockets) and checked those instead. Yes, it would have taken a couple of extra minutes, but certainly a huge concert is worth that.
Even if you are right (that they might just implement the easy ones), you don't actually lose anything by adding the clause. At worse case, you're as bad off as if you didn't have it. Not exactly a "counter-argument" since you don't actually lose anything.
As for why not just pick something else...It's hard to tell without the full list...how do you test that something can hold 600lbs? Even if there is something relatively easy, say, that sockets are X feet apart from each other...again, what's the harm in 1 additional quick check? (and if you say their reputation, I'd argue it might have helped their reputation as oppose to harm it)
Also, the other checks, like sockets support X amperes, are much more likely to be satisfied accidentally even though they didn't read the contract carefully.
Having worked at venues I can tell you that the person that did this job was likely "local crew" and someone who was probably thrilled to be doing ANYTHING for the band, MM's related or not.
Instead of such a ridiculous demand, they could have just picked a couple of random, but useful clauses from the contract (like the number of sockets) and checked those instead. Yes, it would have taken a couple of extra minutes, but certainly a huge concert is worth that.