I don't think the grand leaders of the church thought this through. The real purpose of a mission is to create devout followers, not through conversion, but through brainwashing the missionary force itself. Conversions through baptism was a side benefit. Now, a mission will no longer consist of the constant rejection that one is faced with by going door to door. That rejection was a key part of building guilt and reliance on the church. It was also busy work, it gave the impression that you were "working" and doing something active for the church. Now, Members may bring a person or two for a tour, but those will be few and far between, and then probably just the curious. Not to mention it's incredibly passive. Missionaries will be waiting for members to do the work.

Missions will cease to be a struggle constantly fraught with guilt, (if I was only more worthy, I'd find a golden convert)... Now the guilt will be shifted to the members and not the missionaries. Missionaries can now say "The members in this ward are terrible, if only they were more worthy". By shifting the guilt and busy work, a major factor in the brainwashing is removed. It's easy to say, if you were worthy, you'd find someone, it's harder to lay that same blame when you have to rely on members to bring people to the missionaries. The missionaries now have an "out". If you try to lay the blame, they can say, "What about the members, it's their worthiness that's the issue, not me."

Letters home change from "We went door to door all day. I pray nightly for a new convert to teach, if we are worthy enough we'll find someone." Now they will be, "We sat around the church today, no one was signed up for a tour, the members here are terrible. We decided to clean the stench out of the bathroom to keep busy."

I think if I had served a mission of this style I would have left the church sooner when I got home, maybe even immediately. The last thing the church wants is these young people with guilt free time on their hands to think about what they are doing, this new policy change will be giving them exactly that.