Well at least in the past when real popes wrote, athiests had something to grip onto and accept or consider. And then if they considered or wrestled with it and made objections Catholics could employ apologetics in an attempt to bring the athiests to the truth.
It seems like Karol Wojtyla's gibberish did not even allow for that reader to begin any possible process of converting to Wojtyla's religion, let alone to the true Faith.
Furthermore if the book is just full of "abstract gibberish" that could also be a cause for shallow Catholics who think Wojytla is the pope (no lack of that species around!), to conclude that Catholicism is just a bunch of pious "abstract gibberish" that really "means nothing".