This thread has gotten.. interesting to say the least
I think there's a general misunderstanding of what is being asked for, or rather the feelings behind this sort of request.
Having a "Clearance Required" check box in no way excludes players any more than the current options to set what jobs you'd like in your party. If a Party Finder creator decides they want to do a run with 5 Dragoons and sets up the conditions reflecting that, it's entirely within their right to do so regardless of the fact that you may have an ilvl 110 BRD and feel you should go. You have the option to ask them if they would like to change the conditions however and they have the right to do so or to refuse your request.
Players need to understand that the Party Finder is essentially a job / request board, It's designed for players to be able create a party tailored to their specifications. It isn't a free-for-all that entitles everyone to join every party posted even if they don't meet the requirements the leader is asking for. That mentality is inconsiderate of the playstyle and wishes of the person who took the time to set the conditions for their Party and also to the other players who actually joined and meet those requirements.
There is nothing elitist or exclusionary about this, as every player has an equal chance and ability to create their own party with their own requirements in the party finder should they wish to. When it comes down to it, the only party you have a right and are entitled to join is the one you have created yourself.
Luckily the Party Finder isn't the only way to do group content with strangers, the game does offer a free-for-all alternative that does not allow people to set requirements or control the party composition.
It's called the Duty Finder
I think one too many people are taking this personally when it has nothing to do with the feelings or exclusion of individual players, to say so is a gross misunderstanding of the design and function of what the Party Finder actually is.