The list above is not exhaustive and represents just some of the reasons why it has not been possible to emulate the Qur’an to this day.
Do you seriously think that your argument convinces anyone who is not already convinced of the underlying claim?
It is highly unlikely that you could write text that you claim to be by Shakespeare and have it fool scholars. The analysis now done is working very effectively to pick out bits of Middleton in Macbeth, bits of Shakespeare in Sir Thomas Moore, and so on. That's not to say that these conclusions are right in an objective sense, of course, but they have strong scholarly backing across most people working in the field, and a consensus is emerging.
The same would apply to attempting to write extensions to Bach's work: there's now sufficiently detailed analysis of Bach's work that it is unlikely you could pastiche it and not get caught (and it's not as though previously unknown Bach hasn't turned up and been authenticated quite recently).
The same's true, mutatis mutandis, for almost any good composer, writer or painter. If their work is available in sufficient volume to be analysed in detail, then the precise details of their style and technique will be known to a depth greater than the ability of anyone to forge it.
Neither Shakespeare nor Bach are divine, and their work is not the product of divine inspiration. It is highly unlikely, however, that you would be able to construct work purporting to be by them and not be detected. How does this differ from your claims about the Quran?