may be it is worth debating and Audax organizers should try to reach out rather than being self-indulging...
If you look back through this forum, you will find considerable debate about it. Please don't make assumptions
I've spoken to customers of both:
What is it that attract novices to Sportives rather than audaxes?
even if they cost triple ? and offer little food?
Is it the signed route ?- yes, for many. Of course this costs, so a £3 audax is unlikely to supply it.
in many or the availability of GPX?- many Audaxes supply a GPX, so: No.
the advert on glossy magazines
- very much so. Sportives get free publicity every week in Cycling Weekly, who write about many sportives, but barely even covered PBP last time (or the Uk flagship event LEL with 500 riders).
the publishing of timed results?- yup, possibly - of course this makes it a race, so the insurance/legal situation is dodgy - something AUK wants to avoid.
But as I said above, this HAS been discussed, you just haven't come across it (or looked for it?)