Virtua Fighter is probably the game that uses 3D movement to its fullest. It even has two different types of sidesteps!
And in VF, the great majority of moves are perfectly safe on block. It's all about active defense, so evading at frame advantage, evading at frame disadvantage, backstep, boxstep, fuzzy crouch guard. Simply holding the block button is better than nothing but it won't get you far at all.
VF revolves greatly about guessing what the other player will do, and the 3D movement is very important for that.
In Soul Calibur (and Tekken), 3D movement makes a strong difference, but you can get by with a simple block-punish game. It's even easier in Soul Calibur thanks to the guard break mechanic.
So since you can reach a moderate level by playing Tekken and SC while ignoring the 3D factor, 2D players tend to find those two games easier to get into...