Here's a couple thoughts about that card...
First, you haven't been a hassle lately... If magic players didn't try to seek out new ways to win, I would be concerned that the government has put something (else) in our water. Magic is full of analytic thinking 'rule benders'... Its the type of people the game attracts :-)
Its good that you ask these questions - just to keep things clear & to help remind people of the clan rules - which are different from regular magic rules. Clan rules have been established to help keep things fun. Without the rules, we could have infinite instant kill combos running all over the place on turn 2.
In regards to the card you mentioned...
If you are playing with 5 others & you laid that card down, there is a good possibility that one or more of your opponents wouldnt have anything out to sac except for basic lands. In that scenario, they have no choice but to sac a land, thus making the card clearly illegal for clan play.
Now, there is the school of thought that you could wait to play it or only play it when all people have enogh sac-able cards out other than lands. This is obviously going to be tricky to do & it could still lend itself to forcing people to sac lands if their board becomes clear after you have played it. Playing it this way is too clumsy.
It simply is too difficult to play & keep out while sticking with the clan rules. In light of that, I can understand why Kro would just say thats off limits for clan play - because of the fact that it would most likely force someone to sac a land.
Magic is a game we all play to find the combos & concoct cool ways to win, but this card is too near to that line that you need to ask yourself - could this card (or any other card for that matter) sway over that line of clan rules that is established with the intent to foster good sportmanship & keep the games fun?