My objection isn't based on any reasoning or logical correctness of an ear-height tweeter. I just don't like the presentation of a soundstage that sits perceptibly below ear height. I could theorize about how this preference came to be, but I'm not sure it matters. The vast majority of my experience has been with speakers with tweeters close to ear height. I wouldn't have predicted a low tweeter would bother me much. In general, we don't have great acuity for localizing sounds vertically. Logically this "issue" is something that should be difficult to perceive and easy to ignore. However, this reasoning is in conflict with the reality of my perception during my audition. I wanted to love the S7T. I have been advocating for speaker companies to build something like the S7T for years, as it shares many attributes with my own DIY creations. I still think there is merit to this type of design, but I've realized that (at least for me) the tweeter height is important. With a symmetric array design, a speaker with a tweeter at ear height gets very tall, so I understand the inclination to lower it.
The last thing I want to do is create an issue where there is none. I know how powerful expectation bias can be, and I wouldn't want others to see a low tweeter and automatically assume it will bother them. On the other hand, before spending a lot of money on a tower speaker with a low tweeter, I would recommend performing a bit of testing to see whether or not you'll be satisfied with the height of the audio reproduction. It should be pretty easy for anyone with bookshelf speakers to put them on something that places the tweeter at a lower than typical height and see what they think.