Its certainly possible that Summoners could kick ass. That is why I'm trying to make one (just 5 more levels to go) so I can explore the possibilities first hand.
In terms of judging the class by existing players, well that is the only evidence commonly available. How do you discount that evidence? Do you assume that the existing players of Summoners lack the intellect, imagination, or desire to excel at PvP? These are all possible explanations, but require that we somehow explain the bias of such players towards Summoner. I think the real cause goes in the other direction. The Summoner class is not attracting PvPers in the same proportion as other classes due to its history of not dominating PvP as much as the usual suspects, Pyromaniacs and Berserkers.
You are right about Spirit being a waning strategy. My perception was biased. Now that I look around I see that there are only 2 spirit class players in the top 20, and spirit is only half of what is keeping me there.
The potential of summon charms is certainly intriguing. But I honestly can't recall the last time I was even attacked by a summon deck, let alone lost to one. You point out some interesting charms, but those are L44 and not class charms. Not exactly the bread and butter of the typical summoner. Also, 11 magic over 8 turns= 88 damage (assuming you live that long) seems at best competitive with typical boost tactics, and not even close to what can be done with Ice Spikes and constant boost. What force multipliers exist for summons? All I've seen are things that make them last longer. Longer summons are difficult to wait around for when Pyros are hitting you for 250 dam.
