I did not say they were not seeking God. Plenty seek God zealously and find Him not, because they seek Him not by faith in His Word only, and are more than willing to believe things about God through other things, that His Word does not agree with with:
For I bear them record that they have a zeal of God, but not according to knowledge. For they being ignorant of God's righteousness, and going about to establish their own righteousness, have not submitted themselves unto the righteousness of God. (Rom 10:3)
They were not Sola Scriptura, and so they were ignorant of God and His righteousness, and were instead establishing their own righteousness as that of God, by believing other things apart from Scripture of God. They sought Him not by faith in His Word, but by believing traditions of men apart from His Word. (Rom 9:32)
I said, as you, that if they are seeking God apart from Sola Scriptura, then they are attempting to climb up another way:
Verily, verily, I say unto you, He that entereth not by the door into the sheepfold, but climbeth up some other way, the same is a thief and a robber. But he that entereth in by the door is the shepherd of the sheep.
The door opened to heaven and the Father is the Word of God in the flesh.
Sola Scriptura hears the voice of the true Shepherd only, as heard and plainly known through His Word written in the flesh: Scripture.