Barcelona is just getting ready for bigger games, they realized long time ago that getting good results against ordinary teams do not make their fans happy at all, the games that batter are in champions league and in the league it must be beating ATM and Real, if they could do that then they could keep their fans happy and fans are customers because if they are happy then they are willing to spend more and as we all know they need that money.
Games like Elche do not even matter that much, they could end up losing if it didn't hurt their league chances and nobody would care, but they need a win because of the league situation so they are going to get that too.
I doubt anyone will care if they lose to a weak team. The fans in that case, on the contrary, will be unhappy and look for reasons in the coach, in the team itself, and so on. The main point here is rather to beat strong opponents and not to lose to weak ones, that's all. So far the championship race is looming this season, although it's too early to talk about it.