Piggybacking off of what Ness just said and taking into consideration Fixi's comment as well, I'm fairly certain myself that the majority of people who snipe would prefer to clicking over releasing as it seems to only allow more freedom of movement and ease of aim without holding down the left mouse button. It'd also be my assumption that not having to hold down the left click would only make things easier for new players as well being that they're probably already struggling with moving and aiming at the same time anyway.
This being said I really don't know how the votes are currently in favor of the other. (perhaps trouble interpreting the poll's wording?) I don't even know what could be said in favor of hold2charge being easier for newcomers to legions.