Since a French bishop had already approved the translation, there were political problems involved as well.
So it's not an all-out condemnation of Scripture reading.
Plus, of course, in the intervening 300 years we've snagged an actual indulgence for prayerfully reading Scripture for more than 20 minutes . . . !
With all due respect, your “research” was accomplished in a few hours and turns up a “heresy”? Exactly what heresy did Jansen promulgate that is unbiblical (as opposed to un-Catholic)? Predestination, original sin, anti-semipelagianism, non-reverence for dead men?