Because hat quality has gone downhill over time,
Why does the iDevice and Mixed hats have to separate to begin with?
a) have all 4 winning teams select hats. If two guilds want the same hat: 1st place winners take precedence over 2nd place (as it is now); Flip a coin (or use some other determinant) to decide whether iDev or Mixed gets first choice.
b) allow the 4 winning teams to select hats using the current method, but if a team does not like their options, they are allowed to chose the leftover hat from the opposite GST.