The problem is that there are precious little alternatives.
This article focused on Christians as a primary user of these tools. Put yourself in a Christian's shoes for a minute. You, being a Christian, are convinced your impulses and desires lead you to what is often harmful to yourself and those around you, and most importantly dishonoring to a God who you are convinced is honorable and good.
You don't want to just say "no internet", but much content on the internet is so very well tailored to those impulses and desires. You are often presented with content that requires an immediate internal fight, and you know that some of those fights don't turn out the way you want.
Look, when you are committed to fighting, you'll reach for any tool at hand. I'm not going to wait for a tank to magically appear for me when someone throws a punch at me.
Unfortunately even though these churches are using tools with privacy issues, at the end of the day: it's what is available. And, the fact that the whole concern of personal privacy is often times at odds with the bigger fight doesn't help.