From my own perspective, Bitcoin adoption is a gradual process, it takes time for growth. When Bitcoin first came into Existence, it didn't boom immediately, it took awhile which include awareness period,trial and the likes.
In El Salvador process was not done the way it was supposed to be, the government should have created the awareness of Bitcoin and it's benefits to the citizens before the adoption. It was lack of knowledge that made the citizens withdraw to 10% of it's users when Bitcoin plummeted.
The government should have study her people and understood what should have came in first before the adoption of BTC.