Firstly if your trying to convince someone, I recommend not insulting themThis expedition defeated army of daemons, including possibly-Greater-daemon, back on Vlag. We have reached Dum mostly unscathed and sure as fuck could survive several days or more.
The Expedition wasn't expected to go as lucky as we got. Every single person here was expected to die in Chaos Wastes, and every single person here knew that when they subscribed to going to Dum. How about cease being cowards and panickers and try to actually do the purpose of our trip here - finding in what condition Karag Dum is and relaying this information to Karaz Ankor and Old World?
As to the gist of your argument. Everyone else in the expedition appears to have come to the same conclusion. Snorri is perfectly fine concluding the affair here with the proof of what we've already seen.
There is a batsman demigod standing between us and a mountain filled with possibly hostile dwarves. With a massive forest of age and creepiness factor equal to the Drakwald added for flavor.
Yes we leave empty handed (except for Karak Vlag). Yes we did fight an army of demons (magnitudes smaller that what's in that forest, in prepared fortified terrain while they were weakened and while they were on a strict time limit unable to cast sorcery, and unfamiliar with the area in general). But we are simply not equipped to deal with this.