Audax is about i can do any route if i want between controls.. Are Sportives popular because its easy to compare yourself against others.
Mandatory route , found one says you should follow the route. Whats going on? should it not say you must follow the route.
Organisers carefully design routes and set controls which allow them to recommend a good route on roads which are attractive to ride on and don't pose a level of danger above the normal for public roads. Organisers' assessments of the thresholds for those factors varies. Nearly all rides under the auspices of Audax UK are ridden on 'advisory routes' and a few every year are designated 'mandatory routes' for example Undulates' Mille Cymru last weekend. From your OP it seems to me that you are keen to organise rides which visit scenery and advisory route status with multiple controls (some manned, some commercial, some info) would not achieve the aim. So just designate your routes as mandatory (as Mr Sabine has suggested above): those who chafe at the implied straightjacket can ride elsewhere.
From the Organisers' Handbook:
"Advisory routes must be of the correct distance, with no material shortcuts and without requiring
too many controls. Convoluted routes with excessive numbers of controls are inherently unsuitable
for Audax events."
Audax Uk Regulations:
"9.8.2 The controls are placed to ensure that the rider completes the validated distance.
"(c) Event routes set by the organiser are categorised as ‘advisory’ (riders may take any route between controls) or
‘mandatory’ (riders must follow the registered route).
"(d) Events with Mandatory routes may include unannounced controls and/or other measures to ensure riders follow the registered route."
"Unannounced" aka "secret" though I understand that if an organiser, having set a mandatory route, is going to deploy 'secret' controls they have to 'announce' the fact.
If, on a (normal) advisory route, I choose a variation to the recommended route, I am still enjoying my ride, though maybe not in company for that bit. I'm not comparing myself with other riders when I do a randonnee: I'm riding to complete a long ride which I've set out to complete, and hope for the bonus of company some of the way, good roads (and maybe a bit of off road), good weather and a tailwind all the way, and overall enjoyment (combination of the ride and the achievement). The same goes for a sportive: others may be pretending it's a race but I am not (nevertheless happy to take a wheel if suitable). Does that make sportives more popular - don't know. I think the supported nature of sportives is what makes them more popular to those who are less self-reliant (eta: and who assess that as good value for money which they have to spare). I suspect this issue has been done to death elsewhere.
If your route has enough climb it will earn riders AAA points. This has nothing to do with the options of mandatory and advisory.
As a (west coast) aside, last time I rode through Cambeltown was at 315k of Graeme's West Highlands and I was 8 hours 'in time', lunching (and then snoozing) in the excellent if busy Cafe Bluebell before a blast (all things are relative) north to Oban in sociable company.