Your reply in itself shows that Calvinism is only for those who are well-versed in the works of those two theologians.
That simply doesn't follow, so I think you misunderstood my reply. Anyone even remotely familiar with the likes of R. C. Sproul or John Piper will know that (a) Calvinists don't necessarily believe they are intellectually superior to non-Calvinists, and that (b) Calvinism is not necessarily a denomination for the intellectually superior. Such men as these exude humility in all they say and do. The lives of people like Sproul and Piper demonstrate love, humility, compassion, a servant's heart, etc. There is no indication of intellectual snobbery to be found. And as a Calvinist it is likewise my desire and aim to see the works of the Spirit manifest in all that I say and do, too, just like those men and other renowned Calvinists (e.g., Charles Spurgeon, Martyn Lloyd-Jones, Alistair Begg, and more).
And Calvinism is not "only for those well-versed in the works of those two theologians" or any others. It is for all who are weary and heavy laden, for we preach peace with God found only in the gospel of Jesus Christ.
Honestly, many Calvinists I have met do seem to think themselves intellectually superior to the rest of Christendom, so it is not an assumption but an observable trait.
But perhaps, as you mentioned, it is a zealousness. Whatever it is, it is certainly offputting.
I just want to point out, here, that this isn't exclusive to Calvinists. It's a very human sin that can be found everywhere. There are Arminians who represent an attitude of intellectual and moral superiority in their anti-Calvinist tirades. There are Catholics who come across as superior to Protestants (and vice-versa). There are Christians who seem to think of themselves as intellectually superior to atheists. And so on.
Is Calvinism out of reach for those who are not intellectually inclined, ... ?
Certainly not. My wife is not the least bit intellectually inclined but has nevertheless found a home in our local covenant community of faith.
Although there are great intellectual depths to pursue in Calvinism, that's true of most Christian traditions. However, just because a person CAN go really deep, that doesn't mean they MUST, nor is anyone excluded if they don't. But, again, that's true of most Christian traditions. There are intellectual depths to search out in premillennial dispensationalism (e.g., as found in Pentecostal churches), but that doesn't mean it's out of reach to those who aren't so inclined.
... as there seem to be a number of concepts that the average person would not find worth wrestling with to try and understand.
As I said, the same is true of, say, premillennnial dispensationalism, which can involve some pretty sophisticated and complex terms and issues. Or even Catholicism, such as the depths of Jesuit teaching which is pretty intimidating. (I don't even pretend to understand the intricacies of Molinism.)
Also, there is the extra recommended reading of texts that Calvinists seem to subscribe to.
Name a Christian denomination or tradition that DOESN'T have extra recommended reading for those who are interested.
Again, it's never mandatory, nor is anyone excluded if they have no such interest.
Anyone who is not into such things cannot enter into Calvinism ...
I'm sorry to put it so bluntly but that statement is completely false.
I'm glad there are tremendous theological depths worth pursuing because I truly enjoy doing that, but also welcome in the body of Christ are people like my wife who have a simple faith in Christ.