You are not wrong in that at all Viking not at all, that is in start when forming the bowl the way to go, but if you start lifting the blade out of the bowl again and the wood no longer has allot of material behind it which gives it strength, by backing it up you could start separating fibers.
For finishing of the bowl to make it nice and smooth without sandpaper, you will use your spoonknife in the direction of the running grain, but only if you are sinking down into it , do not try to cut along the entire bowl stop at the centre, cause as you are going up again, you will cut against the grain while there is no material backing the wood up and you will get tear out, and chattering.
forgive me for the vast volume of words yet I find it difficult to describe this in mere words, I will search for a good video, and post one If I find one ^^
Ps these are also techniques I picked up and enjoyed as they really work for me, if there are better ways to do this, please inform us Woodcarving pro's
Yours sincerely Ruud