Why Are Ordinances Necessary Now if They Are Going to Be Performed for Everyone Eventually?

The question in the title of this post is one I've heard numerous times in my life, and I think it is a very good question - and I also think the answer to that question is absolutely vital to an understanding of the Gospel of Jesus Christ and the incredible power of the Restored Gospel as taught in Mormonism.  I hope the following answer to that question is understandable and helps someone who reads this post:

The LDS Church teaches that the ordinances of the Priesthood are necessary for exaltation, but it also teaches that those ordinances will be performed for literally everyone who ever has lived at some point in time when the information becomes available to us. This leads directly to the question in the post title: Sure they are necessary, but why should we care about performing them now? Within our theology, them happening at some point is a given, so it's no big deal for the people who have died, from an eternal perspective, that they happen right now. They might have to wait a little longer if we don't do the ordinances now, but what's a few more years (or even a thousand more years) in light of an eternity?   

My answer is that it's absolutely important for US that WE do them now.

1) Providing the ordinances for every single person who ever has lived removes all "arbitrary" aspects of salvation and exaltation and says we really will be "judged" according to who we become - not what ordinances we perform. That assertion, and the practical proof that we really do believe it, as shown by our willingness to do vicarious ordinances, cuts the heart out of the mainstream Christian arrogance that asserts salvation for the believers in this life and damnation for the non-believers in this life.

That's so important that I will repeat it in different words:

Whether or not ordinances literally are necessary right now is irrelevant, IF we posit that they will be performed in the end for every person who ever has lived. If they are going to be performed at some point, the only "real" benefit of doing them here and now is to those who perform them - particularly in regard to how they see and judge others. In other words, it's all about the effect of those ordinances on us. 

2) It truly is eye-opening to compare the statements in Malachi and the Doctrine & Covenants about the visitation of Elijah as it relates to vicarious work.

Malachi 4:6 says:

And he shall turn the heart of the fathers to the children, and the heart of the children to their fathers...

D&C 2:2, on the other hand, says: 

And he shall plant in the hearts of the children the promises made to the fathers, and the hearts of the children shall turn to their fathers. 

Notice that the verse in Malachi mentions two turnings of the heart, while the verse in the D&C mentions only one turning.  That distinction is critical, I believe, as it seems to say that the "heart of the fathers" already has been turned to the children - so all that is left is to turn the heart of the children to their fathers.  

In other words, at the most basic level, if we are to be united as one great, eternal, universal family of God, the need to perform vicarious ordinances lies in the need to have our own hearts turned to meet the hearts of our fathers that have been turned already.  The need to turn our hearts encompasses ALL of our ancestors - ALL of God's children - meaning we need to seek them out and acknowledge our eternal debt and connection to them, then try to show our love and respect by going to a temple and bearing testimony of our changed hearts by doing something they can't do for themselves but which could and will be done by someone else whose heart is turned to them if ours is not. 

Why are ordinances necessary now if they are going to be performed for everyone eventually?  

Our hearts need to be turned.