You seem to miss the part where I said a longer contract also means they can ask more for him once he wants out. It's either/or. They can refuse to sell him and have him rot in the reserve, doesnt matter one jot to me. My point is all this talk about honoring your contract and loyalty is a load of sanctimonious bullcrap. Albeit, Liverpool at the moment is not one of the biggest clubs in the EPL, let alone the world, so being stubborn with Coutinho will lead to young players eager for game time think twice about signing for them. They will look to Spurs, Everton, Atletico, Sevilla etc instead.
From his perspective, this might be one in a lifetime. A footballer's career is fraught with injuries, loss of form due to change in manager, falling out etc. He's not going to win silverwares at Pool anytime soon, and a year or two down the line a big club might not want him anymore. He's doing what he deems best for his career. It's between his camp, Pool and Barca to work out a solution.