Most teams include Zapdos and/or Tyranitar (by most teams, I mean A LOT) which, by themselves, create a shit ton of issues for most BP chains. So in the relatively lower chance that a player is not running either of these Pokemon, there's still the lower chance of running into a player that will use a full chain. Said chances start decreasing when you start playing tournament battles. Honestly, I bet in all my time playing Pokemon, I can count on my fingers the number of times I've run into a full chain just in regular matches. I've only had to face ONE in an actual tournament. Ever.
So once again reiterating what was said by Piro and Hiest - No real need to take action until an actual problem arises. The elephant in the room is a welcome party guest until he actually starts destroying the party.
edit: as an aside @ Heist - I understand the fear people have of losing to someone with a lesser skill base because of a readily available "cheap" tactic that takes little or no "skill" to use. Fact of the matter is that we're going to see that in every competitive game with both strategies and characters. That's why SkarmBliss was so dominant at one point in time. It's why Magneton + Stuff is popular in ADV. It's why Tyranitar or Heracross rip giant holes in teams by themselves. Things become popular, people see that it works and it's powerful, and it's easily implementable in whatever team they're making. Fact of the matter is, if something becomes THAT dominant, it's a matter of learning to get over and around it. Most higher level players are well-aware of how they can do so, and I believe that's what Chris was trying to get at in his post.
To be honest, the real fears people have over full chains are:
1) Having to potentially sit there for 10 minutes doing absolutely nothing while their opponent 6-0s them.
2) Having to hold a BP chain "counter" on a regular team in fear that they'll run into a BP chain, which is frustrating when it happens to them only 2% of the time and you normally have better options (See HP Flying/Whirlwind vs Drill Peck/Roar on Skarmory).
3) Having to LEARN to get around chains with their regular teams, which is:
boring, it isnt uncounterable.
Have a nice day.
Overall, just a fear of having to compromise one's team building/playing style for those low-chance, unlucky moments when they're staring a Ninjask in the face. I'm pretty sure a lot of players themselves are trying to get those "quick-path-to-victories" themselves when they run into a chain, and when their strategy fails and they get run into the ground for a whole 10 minutes, instead of asking, "how do I get around this regularly?" it's "Ban this! It's cheap! I'm afraid of losing to a scrub player using this lame strategy!"
I'm betting some of the same people would say this also told people to "Learn more metagames or
get better" prior to the auction in SPL. =/
To be honest, clausing BP doesn't even affect the way a lot of people will build teams, but it'll set a precedence for future rulings if these are the kind of grounds we make rules on. We already clause and ban A LOT in comparison to other competitive games to cut down on the luck factor and make skill more prevalent, but there's only so much by which you can dilute a metagame before you realize that some rules/clauses are unwarranted.