Why do women want to be priests? Because they want a career, and they think they are skilled enough to do it. Both reveal a complete misunderstanding of the priesthood. The priesthood is not a career; it is a task given by, and used by, God. The priesthood is not able to be accomplished; it is submitted to and fulfilled rightly only by the grace of God.
I have never met a woman who wanted to be a priest who did not think that she could do the job. "Do" is wrong. "Job" is wrong. Every job in the world that has ever been developed has taken a certain amount of talent. The priesthood is not an issue of talent; yes, a priest should have certain talents because they are helpful to the work, but that is not the same thing (God has used a number of "untalented" men as priests). It is entirely a matter of one's willingness to submit to the work of God and His control over one's life.
This is why (apart from the obvious example of Christ and the law of the Church!) women cannot be priests. Those who want it are seeking it for all the wrong reasons. This does not mean that all men who seek the priesthood are seeking it for the right reasons, but that if one is unwilling to submit to the basic rule that only men are priests, then one cannot possibly submit to the grace of God needed to fulfill one's duty as a priest.
Thus, we can see why real (male) priests can fail. They have the same misunderstanding as someone who not allowed to be a priest, but is seeking the wrong things in that role. They seek it as a career and think that they have been trained well enough to do the job. Any man who thinks that he is capable of being a priest, is in for a sad experience if he is ordained; we are not "capable" but our Lord Jesus makes us capable. He might sneak by the Bishop and receive holy orders (it has been done many times), but he will not have a godly or an effective ministry.
Whenever someone comments on the priesthood as my "job" I try to let them know that I am unemployed. I have been appointed to a task within the Church, and do not have the time or ability to take on an actual job. We as priests are merely the men that God has called to serve Him by serving His people. May He alone receive all the glory.