Abuse of Exclusion?

In the recent Spingold finals, each NS pair replicated this auction, vulnerable:

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and each went down one trick, missing a great opportunity for a big pick-up.

I do not know about their methods, and so am assuming 2/1 where South’s 2♣ is natural and game forcing and 2♠ promises three trumps (although it delivered only two, albeit both honors and with a not very attractive alternative call of 3♦).

I find fault with the exclusion call.  North had two suits with third round losers.  How can exclusion have helped discover if those losers were covered?  

I come to the issue with a prejudice.  I rarely accede to playing exclusion.  In my peer group of partners, I have found exclusion to be employed when there is no more than a parlay of a potential slam and a void suit.  What is often missing in the judgment of the user is, ahem, what to do with a side suit third round loser.  Personally, I would avoid exclusion as North unless I were dealt something like KQTxxx, KQJxx, AK, –, or, at outer edge, maybe the same hand with a small spade morphing into a small diamond (KQTxx, KQJxx, AKx, — ), but still hoping for more possibilities of outside cards that will make a grand such as AJx, Ax, ?xx, ?????, where the ♣A or ♦Q make grand cold and many other possibilities for a thirteenth trick might make grand “good enough”.