I’m also very much for an account bound commander icon, as opposed to the current character bound one. My reasons are simple and have mostly been mentioned above.
With the high cost, aquiring a commander icon is a group effort for most people, with entire guilds chipping in to supply someone, a player they feel is capable, with it. However, as things are now, instead of actually giving the right to be a commander to that player, it is given to a single character only. This ends up forcing said player to play with only that character (in WvW or where ever the icon is needed), as players that received the funds for the icon from their guild members or the community generally tend to take the responsibility of leading their respective guilds/server seriously. But that shouldn’t mean part of their fun gets taken away, and there are plenty of players who find it fun to regularly change between their characters. It doesn’t feel fair to me this way. But neither does it seem fair to ask a guild or community to cough up 100g again to supply another character of that same player with the icon, not even if it’s a huge guild/community that can relatively easily rack up such a sum.
I also don’t think that making the commander icon account bound would create a sudden influx in the number of commanders present at any given time. Personally I have no interest at all in having it, and I think there are many players who feel like that. Having that icon displayed makes you far more recognizable, and if you keep getting defeated (even if it might not be your fault), or make a mistake, it’s far more likely that the other players will hold you responsible for it. And again, there is the cost, even if it were account bound, I still don’t think too many ‘normal’ players would like to save up such an amount themselves for the single purpose of being able to lead a squad. (As for trolls, there are probably plenty of ways to be annoying even without having to make and spent a 100g for it)