I asked my bandmate why he chose to play the BASS instead of a guitar, he replied
"Well look at how many guitar players there are compared to how many bass players there are, who has a higher chance of getting a gig?"
That was his reasoning.
But it is also I believe, moreover, personal choice.
I ALMOST chose to play bass instead of guitar, but my "soul" just felt the guitar more.
The bass guitar sets the backing rhythm to music, a STRONG backing rhythm.
Yes, a band can still be great without a bassist (i.e. WHITE STRIPES/The Doors) however, a GOOD bass player CAN make the music more organized and edgier.
Here is another thing I've noticed.
The bass guitar is the most vital instrument in some cases for some band's STYLES.
After listening to the RAMONES 1976 album for the 100th time, I turned off the treble and upped the bass and vocals on the whole record. And honestly, it sounded exceptional.
Joey Ramone's vocals and Dee Dee's simple bass patterns and his tone worked magically together.
Throw in Johnny's heavily distorted guitar in there and it is something COMPLETELY different.
One of my friends who is a bass player