I think the answer to your question comes down to faith. First of all, you might not agree, but it is logical to have a governing body. Jehovah has always had representatives taking the lead in his theocratic government on earth. Acts 15 describes this arrangement for the first century Christian congregation. Acts 16:4,5 shows that the congregations followed the decrees that were decided by the apostles and elders from Jerusalem.
Please allow me to quote from a 1990 watchtower regarding the governing body in the first century:
"While all anointed Christians collectively form God’s household, there is abundant evidence that Christ chose a small number of men out of the slave class to serve as a visible governing body. The early history of the congregation shows that the 12 apostles, including Matthias, were the foundation of the first-century governing body. Acts 1:20-26 provides us with an indication of this. In connection with a replacement for Judas Iscariot, reference is there made to “his office of oversight” and to “this ministry and apostleship.”"
Now comes the role of the faithful and discreet slave who was assigned to be the master's steward, which included dispensing spiritual food to the individuals within the household of God. Witnesses have published that the modern day "official" appointment came to be in 1919.
Firstly, wether it is in 1919 or at another time, Luke 12:43, after describing the faithful Steward says "Happy is that slave, if his master on arriving finds him doing so!". So there would come a time when the master would arrive to inspect if the slave or house manager was taking care of business or not. So the question is, when did the master arrive to inspect the slave's work?
To do this, Witnesses point to the beginning of the parousia and then make some calculations when examining what was happening in the world and within the organization. This is where faith is required as I mentioned in the first line. As a Witness, I understand completely your view and realize that you either believe this or not.
Witnesses point to 1914 as the year of Christ's heavenly enthronement. I understand this date has been debated on this board so I'm not going to get into that now. I'm just stating what we believe in order to answer your question. Returning to the topic at hand, it is logical to think the master, Jesus Christ, would come to inspect the work of the slave after his enthronement since up to that point he has only been sitting at the right hand of God waiting for this time.
I know you know this already, but just to keep up with the timeline. According to the book of Revelation, Jesus had to take care of some business in heaven as soon as he was enthroned as the Messianic King. So the "inspection" must have happened after that heavenly war. So now the war in heaven is over and it comes time for the new King to focus on the earth. The first thing he does is inspect who has been doing the work of the "slave" or "steward". Here is where the organizations history comes into play. I understand that readers or posters here will have some sort of conspiracy theory on this and will criticize what was happening during that period of 1918 to 1919, but the Witnesses believe that upon inspection, the master found only one group attempting to do what was right.
Again, I apologize, but allow me to quote from a watchtower on what the Witnesses believe:
"On arriving to inspect his slaves in 1918, therefore, whom did the Master, Jesus Christ, find giving to his body of attendants their measure of food supplies at the proper time? Well, by