This has been said a few times but in my experience this is the position I usually hear the "spiritual, but not religious" thing come from.

Don't let semantics get the best of you. Spiritual and religious can mean the same thing if you want them to, it is your perspective. It appears that the perspective of most other people using label "spiritual, not religious" are implying a dissociation from organized religions and/or set-in-stone philosophies. The author could be right in calling this group "fence-sitters" but is fundamentally wrong in assuming that a choice must be made (beyond his personal choice on the matter).

"It takes wisdom to be confused."

Jamie brought up a great point that the word religion/religious isn't even agreed upon, so how can a subset(?) of that label be accurately attributed as being a religion or religious.

It irks me when people use language because I know they mean so much more than the labels I hear strung together. It takes more than a few words to get a message across accurately, patience beyond "spiritual, not religous" will be necessary to understand what an individual is intending to communicate. Listen a while longer