Even now, whilst I believe we have a good shot at the title and are capable of achieving it, I also, in contradiction, don't feel confident enough that even top 4 is 100% guaranteed - although granted something would have to go very wrong for us to drop out now. So if Poch had taken the view as far back as October or November, as you suggest, that the league should be the main focus, I would definitely have worried that we were putting all our eggs in one basket far too early in the season. At that point we had two paths to CL and it made sense (to me) to give them equal priority. Maybe now, 2nd in the league with 9 games remaining, where we know exactly who our remaining opponents are, it makes sense to give the league priority. I don't think it would have been a good thing to make that call 4 or 5 months ago, or even 1 month ago. To some extent it may depend on whether winning the EL is seen merely as a route to CL, or as a good opportunity to win trophy in its own right over CL. If we are looking first and foremost at CL, rather than trophies, then the league route probably does now take priority, but it didn't a few months ago.
Mate, I totally understand your frustration. Especially as you gave the time, effort and expense to go out to Germany, where, like most of us, you would have had visions of us battling hard against Dortmund and coming away with, if not total Glory, at least something close. My worry about the bit of your post in bold above is that if Poch had started with some key players (Dembele, Lamela,Kane, for example) and if Dortmund had still managed to run rings around us, would Poch have been able to take them off after 60 mins, or would he have had to keep them playing the full 90? I can't imagine with us being under the cosh that taking off Dembele for Carroll, or Kane for Chadli, would have been the right thing let alone well received. I honestly believe he gambled that the starting 11, plus bringing key players off the bench if necessary, would have secured us enough to take back to the home leg. It clearly didn't work out, but I don't think it was a conscious decision to play a weak team nor to throw the tie, nor to disrespect the travelling fans or Dortmund. We are suddenly in a position where the league title is possible. For me, the league title is the biggest prize of all. As fans, we may have different views on whether possible = likely but it would be wholly negligent of Poch if he didn't now give the league a priority that might not have been due even a few weeks ago.
I can say all the above when trying to be objective about situation in which we find ourselves, but it doesn't mean I am not hugely disappointed at Thursday's outcome, nor that I think Poch was 100% right with his gamble. But I think I do understand why he took that gamble and it is really unfortunate that true fans like yourself have been left with a feeling of being let down when I am sure that was the last thing that was intended.
(As an aside, given all we know about Dortmund and the Yellow Wall etc., I felt so proud to hear our fans singing out loud and clear. Not meaning to sound patronising at all, but well done to all who were there).