I dont think they will stop backing out unless they are held accountable.
EX: No show, No reschedule or No communication will result in loss pushing the clan that showed up further up the ladder.
I dont think any ladder site is willing to moniter the matches for no shows, cheats and such. You can make all the rules you want but if action isnt taken against those who break them over and over again you might as well not have made the rule in the first place.
Or perhaps it all comes down to other clans not really being serious about matches. In that case maybe someone could come up with a good ladder site that only enrolled serious clans looking for matches day in and day out. That would be fun. Playing against other people that dont cheat and show up.... That would be real nice. 