It's true that most Protestants have long-abandoned the things that their Protestant Fathers professed - but that is the nature of Protestantism.
To splinter and to continually splinter is the true spirit that gave birth to the confusion of Protestantism. Unfortunately, this has morphed into tens of thousands of disjointed and perpetually-splintering sects that ALL teach different doctrines while ALL claiming to have the "Truth."
The abandonment of the doctrines and precepts of God have given way to the doctrines and precepts of mere men (Matthew 15:8-9, Mark 7:6-7):
Some Protestant denominations believe in baptismal regeneration, while others do not.
Some believe in soul-sleep, while others do not.
Some believe in the total depravity of man, while others do not.
Some believe in the Holy Trinity, while others do not.
Some believe in doctrine of “once saved, always saved”, while others do not.
Some believe in a pre-tribulation “Rapture”, while others do not.
Some believe that only those who were predestined will make it to heaven, while others do not.
Some believe that some were predestined for hell, while others do not.
Some believe in a woman’s right to choose abortion, while others do not.
Some believe that practicing homosexuality is a sin, while others do not.
Most believe in contraception, while others do not – and the list goes on.
What a mess . . .