AGAIN you'd be locked into Ferelden.. I don't understand how many times I have to say it. It's like your not even reading my post. It doesn't matter if he has a far greater reach than Loghain. YOUR TRAPPED! Ferelden is crawling with darkspawn at every corner, whether this is a good or bad design, thats how you came to be in your position. You could play dead and hide but that won't matter at all when the darkspawn are crawling up your boots. The chances of you getting out alive? Slim! You are a warden, your job is to kill the arch demon, and you were forced into becoming a grey warden through whatever circumstance before (prologue).
Even if you did escape, you'd leave behind everything you ever knew, or anyone you ever cared about at all to die. By the time you came back, it'd be too late to save anything in Ferelden. It takes multiple nations to stop the Blight at its peak strength as someone already said. So your going to become a grey warden, to run away and eventually be claimed by the calling? What?!
There are many reasons why you'd want to stop the blight before it consumed everything you knew. Once you are a grey warden, your life is about dark spawn. it is logical to assume your best bet is to deal with the dark spawn before it becomes too great to contain in just Ferelden. Each passing day you have to kill more and more, and more lives are lost as a result. I just cannot fathom how you'd think running is logical when you could die on the run to any corner of Ferelden's borders filled with darkspawn.
I am reading your posts. Unless I missed it somewhere however, I haven't seen any reason the Warden would have a more difficult time escaping than the hundreds and hundreds of refugees who made it out. We know that an enormous number made it to Kirkwall, for instance. I see no reason to believe that there are no other avenues of escape.
The Darkspawn aren't an organized force in the sense of traditional tactics. They don't build large-scale fortifications, they don't circle past encampments to cut supply lines, they don't take and hold territory. They ravage, pillage burn and move on. This means they aren't going to be guarding escape routes. They may stumble across them, but it won't be a massive, organized effort.
As for it being the Warden's "job"? What if she was an unwilling recruit? She wouldn't care much about the job then. What if she thinks it's better to make a stand it Orlais, with it's standing, professional army and Grey Warden cadre? Then she's still doing the job, just in a different way than the story took us.
Everything we know being destroyed? I frankly don't see the mage or city elf shedding too many tears over that. Even if they did, that doesn't mean they have any hope of saving anything.
Yes, of course stopping the Blight in Ferelden is a good outcome. Stopping the Blight before it reaches the surface is even better. Having the dwarves outdig the Darkspawn, find the next Arch-Demon before them and pre-emptively kill it is even better. Using magic to travel back in time and stop those rascally Magisters? Best.
Just because something is an ideal outcome doesn't mean that it's likely, or even possible. After Ostagar you have yourself, Alistair, Morrigan and Barkspawn. You are not only fighting the Blight, but the entire Fereldan army and every bounty hunter in the country. It seems perfectly reasonable to me that someone could look at that and say "not salvagable".
I also still have not heard an argument as to why dealing with Darkspawn on your way to Orlais is any more dangerous than trying to fight the bulk of the horde.
There is nothing illogical about choosing to fight from a position of strength rather than a fractured and hostile nation.