how do u figure. 1. it gives the proper base to properly attach a safety cover. 2. it prevents heaving in the weather. i can show someone a ton of jobs that were done with concrete under them and they are all prefect and some are old installs. yes i can also show the same without concrete, but most are not as good as concrete ones than those without. the only way you will get heaving with pavers on top of concrete is if the concrete below totally fails.
I have training and certification from the Interlocking Concrete Pavement Institute which is largely viewed as the authoritative North American Industry trade group on patio pavers. Concrete is not their recommendation for base material.