Don't ruin this for me, Dragonhelm!
LOL!
Gave up, or were abandoned. What /actually/ happens at the end of Summer Flame makes no sense within the setting canon. It's ludicrous. /Everything/ that comes after is a travesty. Honestly, I too wish the setting could move forward rather than start over -- I hate reboots. But I don't see how you spackle the hole in this drywall.
Summer Flame was originally meant to be a trilogy, but the Powers That Be (with the Finances That Were) of the time told Weis and Hickman that it was going to be just one novel instead. In my mind, Summer Flame was written as an ending to the series.
If you want my personal reason, it's because Mina is the most thinly veiled, phoned-in, taking-out-someone-else's-garbage wrecking ball in all of fantasy fiction. Nothing affects her, nothing can stand in her way, she single-handedly kills or destroys everything of prominence in the setting, and in the end she is exonerated of any responsibility for her extensive crimes and rewarded. I expect to see character arcs like that self-published on the Kindle store.
I suspect everyone involved at the creative level in that train wreck "has an idea" for a setting reboot. I know I would.
I mean no disrespect to the authors -- they made bad lemonade from spoiled lemons. I've never stopped reading Weis or Hickman in other settings and have never found them as wanting as they were in the War of Souls trilogy. I blame the corporate interference that was originally responsible for the Fifth Age. The War of Souls is just an abortive attempt to get back to baseline. Alien dragons indeed.
In short: Dragonlance /should/ move forward. But the Age of Mortals was a /mistake/. I have respect for people who own up to mistakes.
There was a lot of heavy editorial control over the Fifth Age era of Dragonlance. It was a time when novel and game lines were not talking. Poor Jean Rabe gets far too much blame for this era when she was just doing work for hire. She's a really nice lady.
For those who didn't like the post-Summer Flame changes, I highly recommend checking out Legends of the Twins. There are six alternate timelines in there, three of which I wrote. One of them is called the Age of Dragons, and is an alternate timeline where Takhisis doesn't steal the world. In other words, "What if the Fifth Age didn't happen?" It's set up to have a lot of political tension through a Cold War, but you can ignore that part and just play a regular Dragonlance game if you want. If I was to run a Dragonlance game at this point, it would be in this timeline, with a few modifications to allow for some Fifth Age-isms (i.e. the Legion of Steel, ambient magic).
A friend of mine from Dragonlance circles was once had the opportunity to tour WotC shortly after they bought out D&D. He was asked if he liked 4th Age Dragonlance or 5th Age. I think his response was that he liked Dragonlance. So even the company saw the two eras as separate entities.
The War of Souls and 3.5 run of Dragonlance books were meant to bring a split fanbase back together, while offering something new. I think, overall, a good job was done. The one thing I disagree with is that the novels seemed to focus on empire-building rather than focusing on a group (or a few groups) of companions who were like family to each other. What makes Chronicles so great is that sense of family.
Of course, in my mind, the 3.5 run of Dragonlance books under MWP is the golden age of Dragonlance gaming. I may be biased, of course!
The DMG says very specifically to make the world as you wish. You can play in any era or shape the setting to whatever you wish. Dragonlance has much to offer, as do all the settings.