I've taken my trees private for much the same reason. I'm happy to share information with trusted research partners and those who contact me for more details. I'm not happy with ancestry.com's failure to fulfill their stated level of service.
Over the course of my membership here, I've met and become good friends with some previously unknown 4th cousins, with whom I correspond on an almost daily basis. Two of us made a research trip together last year, digging back into the earliest records of our common 4xg grandparents.
I think the organization at ACOM has grown too quickly without sufficient safeguards. Something is always broken or not working as it should.