This whole pledge thing is going to back fire on them big time and dry up any desire to give as the unconscious of even the more devote worshipers moves them to give less and less.
I so disagree. You are somewhat correct in that members will give less and less as they realize they don't have to. It happened with literature and it will happen with donations just for the good of the worldwide work they think they are giving to.
BUT
Watchtower already took tons of money and all the Kingdom Halls. They already won. Some congregations will give more than they think they need to and many will give barely what they think they need to. Sure, the rest won't give as much, and as time goes on, this monthly amount will go down. As the money goes down, they can simply not remodel Kingdom Halls and the local members will do their best to keep up the place without LDC. They will close halls that they feel are not profitable.
Personally, I look at Scientology and see Watchtower going the same way. Scientology has the money and is not really concerned about retaining and recruiting so many new members. Watchtower will keep the money and suffer with less members.