I'll bite, despite the 'intelligent only' criteria.
I don't actually want Rafa out. But I do think the topic is so laced with taboos and standard reactions, that any rational consideration of the possibility of him leaving are strangulated before being given any room for consideration.
I don't think there is any way to get around the fact that we have been poor this season. Unacceptably poor. By that, I mean that if we were to make a habit of such a start to a season there's no doubt he should be sacked.
I don't think there are any mitigating factors for this. We lost Alonso, but we spent enough money to ensure adequate replacement. And rafa knew full well the riscs of buying a direct replacement that would not be in immediate action.
I am not too keen on the general perception that Rafa's transfer policy is the best of possible worlds given the constraints placed on him. I think he has made a fair number of mistakes, not just in the purchase department but also in regards to players offloaded (and not offloaded - why is Dossena still here?). When Rafa wanted to sign big names, it seemed largely overlooked that had he not focused on casting such a wide net in signing players that were only moderate upgrades on what he inherited, he could easily have found the means to sign big names every season before the Americans came in. Parry has been largely blamed for our inadequacies in the transfer market, but that is to me a truth in need of qualification. Whatever you think of Houllier's abilities in the market, he had by all accounts an exceptional relationship with Parry and seemed more than happy with with the way transfers were conducted in his time here.
The Keane saga was a fiasco from beginning to end and one that, regardless of mitigating circumstances, does not reflect well on him. And the gnawing question of whether having an extra striker with proper experience might not have given us those crucial extra points to win us the league last season. Forget about the sale of Keane being premature, and consider what a player like Bellamy could have added to the side last season.
I find most of his talks about spending power and Man Utd defeatist and tiring. If you look at what someone like Mourinho says about player psychology, and also what his own (and former) players say about him, it is that he knows how to instill a belief in his players that they are the best of the best. Rafa doesn't seem to truly appreciate the effects of such a mentality. [little did I realise how much more true this would be of Roy a year later]
It seems more people are beginning to acknowledge that Rafa is not exactly a an exceptional people's person, which is something that has concerned me a bit from the beginning. I was struck by a comment he made not long after coming here that he didn't think, with the way things were in the squad, that he could create results with Valencia anymore. It is a concern for me that his people skills might eventually undermine his longterm capacities. In particular, when faced with a crisis such as this one, it concerns me that he might lose the dressing room faster than he might have done.
I think due consideration ought to be given to the prospect of there being better candidates out there. It's premature at this stage, but if things take a turn for the worse, the availability of genuine candidates will obviously influence whether to make such a decision or not. If there is one major mistaken assumption that has been nurtured under Rafa's tenure, it is that it was necessary to overhaul the squad to such a great degree as he did and that so and so many years of rebuilding are needed whenever a new manager comes in. I don't think that was the case when Rafa took over and I don't think it is the case now. There are several managers out there who have proven that it is quite possible to come in to a good, but trophy-starved, side, supplement it with a few choice signings and create results within a season or two. [this, btw, is also why I am so pleased we now have a director of football]
Then there is the question of the Americans that seems to frighten any rational consideration of this into a dark corner of the room. A lot of people seem heavily invested in the narrative that rafa is Luke Skywalker singlehandedly holding back the forces of the evil empire with nothing but his lightsabre and a tactical notepad. And should he leave, some Darth Maul stooge who cares only for pleasing his masters and snickers at all the money the club will save by not signing new players will take his place, whilst all and sundry in the squad will be dying to leave the club.
I think such considerations are unwarranted. The Americans are not so stupid that they won't want to bring in a manager whom they think, first and foremost, will be succesful (the question of whether they are capable of properly identifying such a man is imo a greater concern) [I was terribly right on this one]. And I genuinely can't remember a good example of player exodus after the departure of an influential manager at a big club. I recall plenty of examples to the contrary though.
I'm sure there are plenty who will disagree with my criticisms above. But I think they are legitimate enough to deserve some room for consideration and allowing for the possibility of genuinely weighing up Rafa's continued qualifications for this job.
Finally, I wish to reiterate that I don't actually want Rafa out. At this point in time, all these negatives don't outweigh the positives for me and I do think he is currently the best man for the job. Nonetheless, we do currently look the most likely candidate to finish fourth. If we miss out on even that, then we seriously need to consider other candidates for the managerial post. And regardless, if we fail to mount a serious challenge a la last season the season after this one, I think Rafa has had so much time at the helm to mount more than one serious challenge that we will also need to consider better candidates.