There is nothing wrong with desiring to understand the nuances of theology. It is when we start to confuse the pillars of the faith that define orthodoxy with non-essential doctrines which have been debated for centuries that we get ourselves into trouble. My own denomination has a wonderful saying for this: "In essentials unity, in non-essentials charity." The essentials are spelled out in our statement of faith. On the non-essentials there is considerable latitude and points of view.
Theo geeks are often not satisfied with latitude on non-essentials. They can be very black and white thinkers for whom latitude is not part of their vocabulary. The problem is threefold. First, in not making a distinction between essential and non-essential doctrines they elevate all doctrine to the same level which the church has never embraced. The various well know creeds of the church are all about the essential doctrinal issues that do in fact matter.
Second, in doing this they often create conflict over issues that were never meant to divide people or the church. When non-essential doctrine becomes a cause of disunity there is usually an underlying issue of black and white, inflexible individuals who are majoring on the wrong things and need to have their views accepted.
Third, narrow theological thinking (we all need to agree on all points of theology) often leads to a theological pride. The focus on getting every jot and tittle correct marginalizes those whose tittle might end up elsewhere and the focus on fine points of theology takes our focus off of the grace of Jesus, the transformation He wants to bring to our lives and the practical application of the Scriptures to our every day lives. When intellectual pursuits and knowledge become more important than grace and transformation the end result is pride and arrogance.
The study of theology ought to engender humility not pride. The longer I am immersed in the Scriptures the more clear I am on the essentials of the faith and the more humble I am about how much we do not understand of the fullness of God. In all eternity we will still not plumb the depths of His greatness and the breadth of His person.