Kraichgauer wrote:
The fact remains, I doubt that anyone other than practitioners of Hinduism are taking part in Hindu spiritualism by doing yoga. So that makes him as much a crackpot as the fundies he claims he has no part of.
-Bill, otherwise known as Kraichgauer
I assume by "fact" you actually mean "opinion."
I generally agree with you that a moderately-religious person can occasionally participate in the customs of other religions/religious cultures without actually threatening their religious identity, for example I can eat matzo without becoming Jewish, or sing a Christmas carol without becoming Christian.
However your claim that "yoga is unrelated to Hindu spiritualism" is highly suspect. The term "Yoga" is often used in the West referring to a set of stretching exercises or "asanas." This is technically "hatha yoga" which is just one element of the larger yoga practice.
I personally am pro-yoga (Hindu origins), pro-meditation (Buddhist origins), pro-rosary (Christian origins) etc. but I am not so naive as to think these practices are belief-neutral. The literal historical origin of the word "yoga" is to overcome attachment to the Self and "yoke" one's spirit to Lord Vishnu and the other Hindu deities like an ox is yoked to a cart. Can you see how this might be incompatible with certain Christian beliefs?
An analogy: Imagine that your friendly neighborhood gym or health club started offering a new workout routine consisting of prostrating oneself towards Mecca to improve flexibility and reduce blood pressure. Of course participation in this class does not make one a devout Muslim any more than eating an Easter Egg makes one a Christian. But would a fundamentalist columnist be a "crackpot" to raise questions about whether this "exercise class" is compatible with a devout Christian lifestyle?