Whilst I agree with the basic thrust of your argument, I can understand why so many of Simon’s files have not been printed. In many cases the same basic file is used across several scales adapting wall thickness and level of detail to be appropriate. That does not mean that they are unprintable, just that they have not all been printed.
My SNCF Corail compartment stock files were made freely available to anyone who wanted to print them. But they were only in 1:160 scale and many had not been printed by me. Each file is an amalgam of standard pieces - basic bodyshell, standard windows, standard doors, standard air con grilles, etc. and all are perfectly printable. A friend in France has printed hundreds of them for those without home resin printers. And the files are free to use though not free to redistribute.
I have been asked to rescale them larger and smaller, but unsurprisingly no-one so far has been prepared to pay me to do that. Simon has already completed all that rescaling work upfront and has found , like me, that there are not customers wanting to pay for the rescaled file.