The scriptures teach God's providence and man's choice. Molinism reconciles the two cleanly. In explaining scripture, Calvinism has to 'explain away' man's freedom and Simple Foreknowledge has to explain away God's providence.
Consider Acts 4:28 and Matthew 23:37 :
Acts 4:27-28 - “For truly against Your holy Servant Jesus, whom You anointed, both Herod and Pontius Pilate, with the Gentiles and the people of Israel, were gathered together to do whatever Your hand and Your purpose determined before to be done.
Calvinist - God planned the events leading up to Christ's crucifixion
Molinist - God planned the events leading up to Christ's crucifixion
Simple Foreknowledge - Only the crucifixion was planned, not the events leading up to it.
Mt 23:37 - O Jerusalem, Jerusalem, the one who kills the prophets and stones those who are sent to her! How often I wanted to gather your children together, as a hen gathers her chicks under her wings, but you were not willing!
Calvinist - Christ wanted to save the inhabitants of Jerusalem, but their leaders opposed Him
Molinist - Christ wanted to save the inhabitants of Jerusalem, but they opposed Him
Simple Foreknowledge - Christ wanted to save the inhabitants of Jerusalem, but they opposed Him
Similarly, Molinism reconciles warning passages with security passages:
Consider Hebrews 10:26-29 and Jude 24:
Hebrews 10:26-29 - For if we sin willfully after we have received the knowledge of the truth, there no longer remains a sacrifice for sins, but a certain fearful expectation of judgment, and fiery indignation which will devour the adversaries. Anyone who has rejected Moses’ law dies without mercy on the testimony of two or three witnesses. Of how much worse punishment, do you suppose, will he be thought worthy who has trampled the Son of God underfoot, counted the blood of the covenant by which he was sanctified a common thing, and insulted the Spirit of grace?
Calvinist - this is a warning to impostors
Molinist - this is a warning to true believers about falling from grace
Simple Foreknowledge - this is a warning to true believers about falling from grace
Jude 24 - Now to Him who is able to keep you from stumbling, And to present you faultless Before the presence of His glory with exceeding joy,
Calvinist - God can keep you from falling
Molinist - God can keep you from falling
Simple Foreknowledge - if you don't start to fall, God can keep you from falling
All things considered, that's hundreds of passages that I take in the natural sense and other have to explain away. I am unwilling to let my system interfere with my reading of scripture.