For a Protestant to say he's sola is to provide his historical bonafides. He at least attaches himself to the Reformation, even if Roman Catholicism goes back to the Edict of Milan. It's his trajectory to gravitas, even if he's superficial and self-serving. However, if you're really sola scriptura, you got to look at what it means. You might read the Westminster Confession from the 17th century, which says (1.6):
The whole counsel of God concerning all things necessary for his own glory, man’s salvation, faith and life, is either expressly set down in Scripture, or by good and necessary consequence may be deduced from Scripture: unto which nothing at any time is to be added, whether by new revelations of the Spirit, or traditions of men. Nevertheless, we acknowledge the inward illumination of the Spirit of God to be necessary for the saving understanding of such things as are revealed in the Word: and that there are some circumstances concerning the worship of God, and government of the church, common to human actions and societies, which are to be ordered by the light of nature, and Christian prudence, according to the general rules of the Word, which are always to be observed.Most evangelicals can't know or judge about anything that the Bible doesn't say and he calls that sola scriptura. Look at certain statements in the confession.
One, this part: "by good and necessary consequence may be deduced from Scripture." Two, also this one, "there are some circumstances . . . which are to be ordered by the light of nature, and Christian prudence, according to the general rules of the Word, which are always to be observed." I have called this, truth in the real world. A major attack on truth is lying about the meaning of things. Scripture has become irrelevant to many basic decisions in life by an unwillingness to understand using the means that scripture says we have to discern outside of scripture. Everything in life can be guided, led, and judged by scripture, so sola scriptura.
My number one go-to example is the Bible doesn't say, "Thou shalt not smoke crack-pipes." Societal norms seem to be where evangelicals will apply scripture using the necessary means God has provided in the real world. Everyone needs more than what is so obvious. Calling a kettle black doesn't win the discernment gizmo from the cracker jacks box.
Scripture teaches and assumes other things other than scripture. Arguments from scripture can't be made without something not in scripture. Scripture is irrelevant before its ink dries with the present spin on sola scriptura. Crazy's got to be crazy. Ugly is as ugly is. More than swastikas are bad.
To be honest, I don't think what I'm decrying will stop. Rock and rap will continue to be called worship. A butch hair-cut will still pass as feminine. Sunday School teachers shall have optic green highlights. Forget church dress. Nothing will be sacred. God doesn't even have to be God anymore. The only ones in trouble will be those who apply scripture to about anything. Just bake the cake. Eat it too.
God cares. That's probably not enough.