Not forced or unbelievable at all. The conflict of interest through betting, and maintaining the integrity of the show are strong justifications. In addition, many of the events didn't involve fucking, and many were curated shows not conducive to audience involvement. Vera's spider event is the closest scenario which could warrant audience involvement, but it not doing so is also justified story wise. Finally, it's an AVN, why should the main character be sidelined during the main events?
Pre-1: Vibrator endurance test between Lucy and Vera.
Pre-2: Vera's cum chalice.
Pre-3: Lucy/Vera competition.
1st: Service round.
2nd: Double dildo round.
3rd: Bukkake - audience was involved.
4th: Vera's shame.
5th: Felicia's shame.
6th: Rose's shame.
The thousands who visit "performance artists". The millions who visit strip clubs, or cabaret. Kathy's shows are much better. There's specialized IRL counterparts too, like donkey shows, where people pay to see whores get fucked by donkeys and horses. It's mostly unproven but I think one case went through court and there were plenty of videos on Luxure where you could see it yourself. The allure of the Carnations show isn't about fucking. Besides, there's club girls for that.
Joe choked Harper unconscious. Frank whipped/bottle insertion'd Serena out of commision for a month. Letting the dirty old bastards fuck the carnations is a business risk and liability, it can jeopardize the show. Besides, some mystery, rarity, and elusiveness keeps desire afire. Just look at Samson with Vera, Thomas with Rose, or many dirty old bastards with Kathy.
I don't understand why everyone wants to see the dirty old bastards fucking the main girls, but TD hasn't been actively avoiding it at all. A suitable scenario hasn't arrived yet. When it did, like the bukkake, it happened. This year's show doesn't have to be the same, but even going by the image of the previous Carnations for precedent, the audience fucking scene was in "Exhibition 3", so everything's consistent in terms of timeline.