If God wants me in Bangladesh I am unlikely to simply wake up one morning wondering where I am and where my house went, and then come to realise I got teleported to Bangladesh because that's what God wanted of me. If God wants me in Bangladesh and I take a leaf from Jonah's book and run away then I imagine God would care about it, just as he cared when Jonah disobeyed.
Likewise to use Paul's analogy of the body, which is mentioned in some book or other, if God is calling me to be an eye but I'm too busy insisting that I'm a really good hand, I'm not obeying. But there isn't a verse anywhere in the whole of Scripture that will tell me that I, as an individual, am supposed to be an eye rather than a hand. God can show me what he expects of me, and the only way he can do that is by speaking in a way that could be written off as personal experience.
The crucial distinction is that I can conclude what God might be leading me to do based on personal experience, validated against God as revealed to us in Scripture (e.g. he may call me to a ministry in prison visitation but a calling to abandon my wife and go and live with nubile young ladies in the tropics is unlikely to be anything to do with God). What God is leading me to do is potentially of no interest to anyone else (with the possible exception of my wife, who is probably going to want to tag along) and any experiences God may send my way don't form a universal theology. If they contradict what God has already given us in the Bible they don't form a sound theology at all, because they can safely be assumed to not actually be from God. If they align with the nature of God as revealed in Scripture then it is ultimately down to me and me alone to decide what, if anything, I am going to do about the perceived call.
How do you suppose some felt called into full time ministry, some felt called to be missionaries, some felt called to be evangelists? Can you show me the Bible verse that says Billy Graham was to be an evangelist? If not then unless you want to say he shouldn't have done what he did perhaps personal experience can carry more weight than you are giving it right now. But despite what Billy Graham did, your calling and my calling may be something that, in human terms at least, looks much more mundane.