Of course, as Real Madrid fans, we will be happy if Xavi stays because Barcelona under Xavi's guidance makes it very easy for Real Madrid to win, especially this season. 
I think it is not because of Xavi but Barcelona management makes it easy for Real Madrid to win the La Liga. 
Xavi has done his best, but he has no ability to develop the squad with lack of financial. Barcelona most players are young players, it is not easy to win the La Liga with young players with lack of experience.
But I agree with you. Barcelona currently has no other choice but to hope that Xavi can stay at Barcelona. Moreover, if Xavi continues to resign, there will definitely be many clubs who will want to use his services.
Yes, many teams want to hire Xavi because they know Xavi has a good ability. Bayern Munich is one of the teams that show their interest to Xavi. But Barcelona wants to keep Xavi, it is surprising Xavi accepts to stay with Barcelona. Barcelona management may tell Xavi to give him some money to develop Barcelona squad.