CSV : Comma separated value. It has commas .
The reason for the double quotes is to enabled nested commas.
Example : 5,"Top,Bottom","0805Y2k2R,TMP08052rt","R1,R2,R9,R11,R14"
- 5 resistors ( no quotes )
- nested block layers : "top,bottom"
- nested block manufacturer part numbers "mpn1,mpn2,...mpnx"
- nested block designators. "x,y,...,z"
That is how CSV works. Has nothing to do with Altium.