For some game systems, statblocks can become extremely long. If you have a statblock for an encounter that includes multiple combatants, the statblocks can easily be multiple screen fulls in length. By having a separate statblock snippet, users can readily move all that material off to another place, out of sight until needed. If your statblocks are short enough, or you prefer having the statblock inline with the topic, then there is absolutely nothing wrong with putting the statblock into a text snippet. Whatever works best for you!