Slightly unfair that: I thought the floor spot duo were very good, with a wide choice of material well-performed. As for the roving support, several of us attend both clubs, and others, on a regular basis: luckily for us, there is a vast array of club nights and sessions to choose from in and around Edinburgh. For the Club Treasurers, it's all "bums on seats", so no bad news there, especially as non-members have to pay more to get in. And you are not in a position to know whether those doing the floor spots have other regular commitments elsewhere on that night of the week: very possibly they do. And they did stay for the whole evening, unlike some who just come to do their floor spot then immediately leave: not very courteous to the guest when this happens.
Last night's main guest has appeared in the past as guest at that same club you are talking about, where he was well received too.

On another tack, and thinking about those clubs who do both guest and session nights: in those I go to, it is very apparent that we have 3 different populations:
Those who only come for sessions and never bother with guest nights (prefer to perform themselves rather than listen?)
Those who mainly only come for guest nights, perhaps attracted by the main guest, and
Those who do support both (which includes club Committee members who have jobs to do!)