I believe we are confusing two different concepts; let me try to explain the best I can:
Intel® Rapid Storage Technology is a software that can be used to implement Intel® Smart Response Technology and I believe we can agree ExpressCache* serves a similar purpose by using the SSD as a cache for the mechanical drive, accelerating it.
However, besides this functionality, Intel® Rapid Storage Technology loads a driver that operates at a basic level, between operating system and (SATA controller) hardware. Whether you use acceleration or not a driver for this hardware component will always be required for the general operation of the computer. If you decide to uninstall Intel® Rapid Storage Technology, Windows* is expected to load its own version of this driver (but no additional software).
We provide a driver because we are the manufacturer of the “Intel® [insert family model here] Chipset SATA AHCI Controller” in your computer (found in Control Panel, Device Manager, IDE ATA/ATAPI controllers).