Of course, it could! Most of the early years of reggae had a minor element of rasta in it an there was so much creativity going on (which went unnoticed by many, but that's another debate)!
Later, a lot of artists jumped on the rasta bandwagon too, and didn't really practise what they preached. Almost everyone was a rasta on the surface and those who didn't conform sometimes faded into oblivion.
Nowadays, a good number of the best roots reggae music (mostly from outside JA) isn't even recorded by people who are rasta people (some sympathize with the cause, though, not to forget that you can get along fine and reason with rasta people even though you are not necessarily one of them). I got into reggae during years when white people understood that rasta was purely a black thing. That's the way i still see things and forever will. Some beg to differ and i won't try to deter them from thinking so. You don't have to embrace things 100 % to share common grounds. Reggae can survive without rasta as a lot of artists who recorded "reality" anthems back in the 80's and 90's were not even rasta,which didn't prevent them for releasing exciting tunes. There are also artists who are rasta but hold it for themselves: they lead that life pure and simple and don't have to shout it out loud abou their faith everywhere. Not everyone goes for proselytizing. There are also artists who never cease to churn ou the same formulaic rasta rethorics, which don't do much for the cause in the end (clichés?). As long as reggae is entertaining and "conscious" and provides nice examples to the youth, is there really more to ask?
On the other hand, rasta could survive without reggae too and there are bonafide rastas who don't go for it, some even ban it from their communities.