Discussing
Is it a good thing that Jon Stewart’s minions are multiplying?

Well over a decade into this new normal of comedy/news/satire/entertainment, are we getting too much of a good thing?

Bransen, I have noted on TC before my concerns about satire so I'm with you trying to combat cynicism. (http://thinkchristian.reframemedia.com/against-satire-almost)
BUT as a fellow fan of these comedians, I think actually they do more than just ironize, even if it is their primary mode. Sometimes they use irony as a way to inform (I'd consider Colbert's hilarious award-winning series on super-pacs a great example) and they sometimes shift toward sincerity, or a call to action, implying hope that things could be better. So I'd say the complexity of this genre saves it from being only cynical.
Regardless, your call to sincere, radical hope is relevant. Our culture can always use more of that!

While I agree with your ultimate conclusion the danger of unfettered cynicism when it comes to loving others. I think Jon Steward himself explains how The Daily Show (and now others) have gained traction because of the simple reality that news outlets aren't reporting but rather pushing agendas:

https://youtu.be/aFQFB5YpDZE

To answer your questions:
- Has Stewart’s irony and satire pushed us closer to desiring and seeking truth?
> For some yes, because it reminds many that the current reality shouldn't be operating the way it is.

- Have they enhanced our public discourse, making us more self-aware about our own biases and more ready to listen to others?
> Yes and no, often it will pander only to those who already sense or realize things are not as they should; or groups/individuals that are looking for affirmation of their own 'rightness'. Yet, look no further to John Oliver's #MakeDonaldDrumpfAgain, and for the week leading upto Super Tuesday the conversation it spurred in many circles.

- What’s the end goal of this mode of rhetoric?
> I believe it's to bring back a shared common center and fairness. It is hard to believe that a majority of those who offer satire are simply contrarians (but some are), rather these individuals often hold lots of hope in what could be if but are extremely frustrated with what things have become.

I think many desire to see the reality of the world we live and can sense the absurdity of what we hear and shows like the Daily Show are calling to task news outlets, candidates/politicians, and others for not doing their job. The purpose of satire is to serve as the counter balance when things have gone astray.

I recently heard a sports talk radio host say, 'We are just sharing our opinion, we shouldn't be considered journalists.' This refreshing statement gets to the root of what we as a society has come to accept as 'news' and that is opinions. In many ways, we all have lost our center when it comes to discerning 'truth' and are left believing that our personal experience or belief trumps everything else. (sidenote: I'd highly recommend binge watching the series 'Newsroom' which dives into the news medias responsibility specifically)

All of this to say, I think satire is needed, if only when it pushes the thing that is being challenged to return or to operate as it should. In many ways... these satirist join people of faith in proclaiming the ache for things to be as they should be, as they were intended.