Actually, its very relevant, because it models the textual stream far more accurately than a 'dirty signal'.
In a dirty signal, with plenty of error and noise, you get a picture that looks like the following:
Here you can see that as noise increases, two other things simultaneously happen:
1. The Signal looks more like the noise and vise-versa.
2. No loud, clean, focused and coherent signal is possible.
This idea of 'coherence' is important, for it is what characterizes and describes the transmission process. If the signal is 'coherent', we know that the transmission process is relatively error-free. If the signal is not coherent, we know that the process is error -prone and 'dirty'.
The problem with the Hort-position, is that it postulates a very unreliable transmission medium, and a very 'dirty' transmission. But if that were true, we could not have a 'coherent' signal at the end of it.
The very existance of the tight, coherent Byzantine text-type points to a clean, relatively error-free transmission process. It is the loose Alexandrian cluster of manuscripts and readings that suggests a 'dirty transmission'.
- the Engineer