Spain's La Liga is mainly dominated by a few clubs, notably Real Madrid, Barcelona and Atletico Madrid. Other teams don't have good strikers and enough players due to the enough budget. A few days ago Barcelona already balanced team with buyern Munich polish styker Robert lewandoski. So undoubtedly Real Madrid and Barcelona two top ranked favourite team would play the final match.
I think you are wrong if you say other teams don't have good strikers or strikers who are hungry for goals. Celta Vigo has Iago Aspas who is very diligent in breaking into the opponent's goal, Raul de Tomas who plays for Espanyol is also very dangerous, these two players are below Benzema in the list of top scorers in La Liga last season. Enes Unal (Getafe) and Juanmi (Real Betis) each scored 16 goals last season, while Deportivo Alaves (Joselu) froze 14 goals.
The reason Real Madrid, Barcelona and Atletico Madrid dominate La Liga is not because other teams don't have good strikers, but because the quality of players that these three clubs have is above average when compared to other teams.