In the context of this discussion on PvP related changes, it makes sense. Unstoppable, Power Surge, and other T9 armor powers don't add significant resistance or defense to a player due to the effects of diminishing returns in PvP. It's actually rather severe, so a player with 120% s/l PvE resistance (capped at 90% for Tankers) for example, would be DR'd down to 60% PvP resistance. Activating the T9 would hardly raise it at all, to say 62% resistance in a PvP zone. Yet, the crash that occurs for those T9s don't get DR'd - so hardly any increase in resistance or defense and then a massive crash. In PvP, at least in organized play, this is essential a suicide button.