Of course a RAID controller has the ability to extract and use the data if it's able to write it in strips the hard drives, all I'm suggesting is that most RAID controllers don't come equipped with the ability to instruct the hard drives in said array how to efficently extract the data simutaneously.
This is what I have been saying all along with a RAID 0 array being nothing but a theory, it's not a true RAID array and was for the most part a server idea that was modified and migrated to the end user. The RAID controller built onto desktop motherboards doesn't fully support STR both ways, it's only been optimized for writing to the platters, and even then, it's not a true full speed STR.
It's difficult to explain, we discussed it briefly in my engineering class