Xavi is too loyal to be Barcelona coach and because of that, I think it was the right decision for Xavi to resign. Because anyway, the financial crisis that Barcelona is going through is really having a bad impact on the management of the team and also the performance of the team.
I think the main reason Xavi resigned is because of the pressure that he is facing as Barcelona boss, especially from the Spanish media and journalists, Xavi has had problems with the press since he became manager and i believe he could not take it anymore. Barca's financial problems also contributed to the Spaniard leaving, but i don't believe that is the main reason he is leaving the club. Barcelona must look for a new manager now, with their limited funds. There is no speculation for now on who will take over from Xavi, but the person is going to have a huge job to do.
Yes, one of the reasons why he chose to resign from Barcelona's coaching chair was the pressure put on him. Even though pressure is a very normal thing that a coach receives, the problem is that I think the pressure he receives is excessive because Barcelona's situation is also not in a good condition. Maybe it would be very realistic when Barcelona could give Xavi everything he wants, but currently he is not receiving everything he needs, while management is putting pressure on him to achieve.
Barcelona should also adapt to their current situation, because I am sure all coaches will give the best for their club. They will do their best when they don't get what they need, especially if they get what they need, the same thing will definitely happen. If Barcelona continues to do things like this then I'm sure no coach will feel at home, unless they get a high salary and also get everything they need.