Don't disparage.
Look at it this way, many people (even Calvinists) were saved under a free-will understanding. So that understanding helped them. Later many became Calvinists (some were saved as Calvinists). But just like those who were saved under a non-Calvinistic doctrine by necessity of understanding some Calvinists depend on Calvinism to understand the gospel (they cannot understand the gospel except through Calvinism).
Calvinism is, to them, the gospel message. Reformed theology is probably the simplest of all theologies. It is basic. Even a caveman can understand it. So it takes away a lot of more complex ideas other understandings incorporate. Why was I saved? Cause God chose me. Why did God choose me? Don't know, but it had nothing to do with me. How was I saved? God punished Jesus in my place paying the penalty for my sins. What about those who were not saved? Jesus could not have died for them otherwise they would be saved.
I would caution you about disparaging other people's understanding because people understand things differently. What if the only way someone could understand the gospel was through a Calvinistic lens? They hold a very simple theology, but faith is still in Christ.
It does not matter if Calvinism is not "deep" as long as it can be a vehicle to communicate the gospel to people. Jesus can make them stand just as He can make you and I stand.
It seems to me what Calvinist says is the gospel really is has nothing to do with what it actually is, because to me the Gospel is the Bible alone. This means with out reinterpretation and philosophy but taking God's word as it is written and not as it is imagined.
MB