In January everybody was talking about us getting Falcao. Now all of sudden they decided that Lewandowski is the real deal and we should change our system as well, putting Messi on the right flank to accommodate Lewandowski.
Plus the whole Dortmund side. Players like: Goetze, Reus , Gundogan, Hummels and Subotic should be bought to strengthen our squad. I hope that you can sense the pattern. People judge a whole team based in the first leg vs Madrid and our whole team based on the Bayern second leg. Even Messi who didn't play gets somehow criticized.
I understand what you're saying; ppl DO have a tendency to like the player they've just seen playing really well. The point is in a lot of ppl's opinion we need to take some of the goal-scoring/match-winning pressure off Messi - what better way to do that than sign another goalscorer. its not a case of changing our whole system, more a case of giving the opposition something else to think about. falcao/cavani would be too expensive, so ppl cast around for a cheaper alternative.
As to putting Messi on the wing; he could be played as AN AM through the middle, behind Lewandowski, but with freedom to roam around. lewa would unsettle the CBs and perhaps make space. He would give the wingers the choice to cross into the box, he would score headers from corners and crossed free kicks/be able to defend corners and free kicks. He would be a target man and an out ball; he could flick the ball on for runners etc. etc.
Barca give up a lot of avenues for scoring/mixing up play/giving the opposition something else to think about by not playing a Striker.
PPl see Dortmund's team go from mid-table obscurity to bundesliga champs to CL finalists in less than 5 years; they pick up cheap players and sell them on for fortunes; they bring through young players. They - and Klopp - are to be admired by any team