Installing anything other than OS in C: drive is asking for trouble later. But even if you install SQL Server in other drives, you will still end up with certain components in C:\Program Files folder.
The rule of thumb is to separate these
1. SQL Server binary
2. Database Data Files
3. Database Log Files
4. Tempdb files
5. Backup Files
Now depending on your server, do you have that many drives?. What if one runs out of space, can you expand it easily. Also with SAN in picture all the drives may be pointing to one giant higly striped pool of disks, in that case all these best practices may be meaning less, unless you have separate large pool of disks for each of these and in many environment that is highly unlikely.