As noble and well meaning as that position is, the issue is when you run into 2 individuals who inevitably claim that they were guided by the Spirit and yet came to 2 incompatible conclusions. Because there isnt a normative authority, we have no way of determining who is truly interpreting correctly.

If we were to set a baseline as to what characterizes a Christian, most people would point to the Nicene Creed or Apostles Creed. This was the creed in which the early church came together and, believing as a united body that they were led by the Holy Spirit, came to a consensus on fundamental doctrines of the Trinity, on the two natures of Christ, on the procession of the Holy Spirit from the Father. I believe its a much more reasonable position to trust this church than a single individual who decided that all councils had erred and that scripture is simple enough to interpret at the subjective, individual level. 500 years and 30k denominations later, I believe we can agree that this isnt the case.