I would say that the SAN admins are nuts if they think that the DBAs aren’t going to worry about storage performance. There is no magic SAN dust which keeps everything running fast all of the time. If you put enough load on the array then performance will be impacted, no matter how many disks there are in the array. The physics say that eventually the little disks can only spin so quickly before they break apart.
In my opinion if they tell you not to worry about performance, then they aren’t worried about the performance, which means that they aren’t going their job.