they arent placed in silver they are put in promos just like every one based on mmr. since they have no rank mmr the match making defaults them to an average mmr which is s5-s4 ish and they make them do their placement games there.
it sucks for silver players cuz u get the newbs and it can hender you a bit in climbing. but they have to put them in the average player base and see if they sink or swim and based on the outcome they get bronze 5- silver 3 out of placements.
i think there needs to be more requirements to start rank other then lvl 30 , they make you have 20 champs *including free to play * for the draft mode of rank. but i think they also need to reach a win total or # of games played, when i started league back at the end of s2 into s3 i was told by numerous guides and videos i needed 300 wins before i was ready to play rank with any concept and understanding of the team as a whole.
however i at 1st tried some rank got bronze ok ... then got silver last season playing 15 games , wining 60% placed in silver from promos. and zero rank games this season. but its not cuz im scare i just dont take rank seriously enough to care. so i play normals to enjoy the game.
but most new players at lvl 30 have no runes nor know how to set up the basic two rune pages AD and AP or have a grasp on masteries, match ups ,ect.
hence why i think they need to have more then just lvl 30 and 20 champ requirement for rank and it think it would make the entire rank ladder *ideally at the bottom *bronze/silver that much better.
just my two cents