@RIOT A request for a dynamic queue change (NOT A REMOVAL)
Since some people are unable to get their main role often if an unpopular role is their secondary (ie: support), could you make it to where, after two games of playing your secondary in a row, you guaranteed get your primary role the next game? If some people enjoy both of the roles equally, you could always enable a toggle option that has the guaranteed primary every third game or the way the system currently works.
This way, the people who main things like Mid/Support (like me) are able to queue up with support as a secondary role without worrying about becoming a devoted support main (when they really don't want to).
TL;DR: Upon playing your secondary role twice in a row in Dynamic Queue, get a guaranteed game as your primary for the next one.