I would like to preface this with an admission that I myself am at current completely inactive due to a lack of PC for the past few months, and thus for instance, I would not expect to see myself on any rosters for the reasons given below.
It would seem clear to me that the reasoning behind Deacon's bid for captaincy is relatively clear (i.e. Playing the NC is about winning the NC -> Less active/skilled players will be less useful towards that goal than active/skilled players -> Only active/skilled players should make the team). Of course, it would be possible to fault this reasoning, either by claiming that the playing the NC is not about winning (in which case it seems difficult to see the point of playing, I understand the idea of not playing to win, but I don't really see the point in joining a competitive league in order to do so), or by claiming that less active/skilled players would be just as useful as more active/skilled players, which would seem purposely contrary and can essentially be dismissed.
Of course, the two complaints from parties who do not deny the logic behind his bid (with an additional third being 'I don't like Deacon_Barry because I'm crazyboy11'), tend to be from two angles. The first is that whilst the aforementioned logic is without fault, Deacon is not necessarily the correct arbiter of skill or activity. It would seem to me that it's difficult to doubt his ability to decide whether a particular player is active or not, in the same way it would be difficult to doubt that of any other active player -- there are limited servers in this game, and if you are never seen playing, it's safe to assume that you're inactive. The argument for his being an appropriate arbiter in terms of skill would be that he has (as others have mentioned) captained either the, or one of the, most successful teams in Europe. Part of this role is of course making qualitative judgements about which players should play a particular map/faction/role, deciding whether they have the capability to do so, and so forth. This in and of itself would appear to suggest that he is able to judge the skill of other players in a way useful to the team which he is captaining.
The second main argument against him appears to be that he is too brusque and tactless (in another light this could of course be seen as honesty) when rejecting players, or making statements about his rejecting players. I'm not entirely sure however that this is by necessity a negative trait in a team captain. Which would be more helpful (assuming that the captain deems a particular player unfit to play for the team): for the player to be told straight away and quickly that they aren't fit to play, or that the captain string said player along, let them on the team but don't actually let them play matches and so on (assuming again that since the goal of playing in the NC is to win the NC, less able players would not be permitted to play matches regardless of their holding a 'ceremonial' role on the team).
This being said, I would assume that captainlust would do a fairly good job of running the NC team, despite being (and I only know this from second-hand sources) very inactive. I just feel that Deacon would take the team further along the lines towards victory than someone who hasn't played the game for a very long time and would thus have to spend time re-familiarising himself with it.