I don't know, it just seems like with so much argument on how to get on the mat...how does anyone ever get to the most important part...training? or, do they?
Well, see, you've just defined the terms of the argument and thus constrained the only possible answer to being the one you want. If training is indeed "the most important part" for someone, by definition, bowing or not bowing is a secondary consideration. But for someone who is considering training, who does not currently train, it is probably not
"the most important part". If religion doesn't make sense to you, think about family obligations: someone wants to train but is responsible for the care of two young children. It would be a bit odd to expect training to be "the most important part" for this person, certainly not as they're just approaching aikido for the first time. Very few people have the luxury of setting all other considerations, obligations and principles aside in order to train; by far the majority of us who do train, still are accountable to these other considerations. Restrictions caused by matters of principle are surely as real as those caused by practical life obligations, don't you think?