BV is a pain in the backside to calculate as it is. I'm guessing that the thinking was something like "let's not bother making this even more complicated or we'll have fans whining about how there's no difference between having 1 non ammo crit slot in a location with ammo and having 2."
Sure. Which is certainly understandable. But the end result is still that some mechs randomly and arbitrarily have a high likelihood of blowing up due to badly allocated ammo. And others don't. And some don't have any chance at all. And it is all incredibly random and capricious. And there is no cost:effect benefit for the incredibly debilitating problem that sometimes is randomly dropped on a mech design.
I mean, yeah, there certainly is something to be said for mechs being able to blow up. But the difference between "A high likelihood of accidentally blowing up" (Marauder, for ex.) and "No chance at all of accidentally blowing up whatsoever" (Flashman, for ex) is a very large one. And the practical application of all of this is that the mechs that have a high chance of blowing up? People just avoid using them. Like, for example, a buddy and I are playing a 3039 era lance on lance fight this week. I want to use a big mech with a couple PPCs. I could use the Marauder, but I'm gonna use the Thug instead, as the Thug has a vastly smaller chance of accidentally blowing up (as well as more heat sinks and armor, but still).
The issue is not that some mechs can blow up. It is that some mechs can blow up, and there is no logic or reason why some are very likely to blow up and some aren't.
If the game designers wanted mechs to blow up occasionally, there were plenty of ways to do that that *aren't* randomly applied and capricious. For example, rather than having some mechs have random suicide bombs in them, why not change the rules as follows:
-There are no ammo explosions. If ammo is hit, it just destroys that ammo bin (or conversely, treat all locations as if they have CASE; treat existing locations with CASE as if they have CASE II). Any time a mech takes an engine crit, roll a die. On a 6, the fusion reactor is breached and that mech blows up.
This gives *all* mechs a equally smallish chance of blowing up on a single random critical. It doesn't punish mechs with ammo more than mechs without ammo. It gives all energy weapon armed mechs an equal chance to explode. Mechs will randomly blow up sometimes, but not due to capricious, random bad ammo allocation. And heck, if using the CASE rule, it wouldn't even make any existing record sheets unusable.
Like, that would be a totally reasonable way to have mechs blow up on a regular basis that wasn't capricious and arbitrary and didn't stick out with examples of things that are obviously just dumb (i.e. putting ammo in an otherwise empty torso location). I mean, like, I'm not actually agitating for this to happen (I can just as easily continue to simply not use the mechs with the inherent suicide bombs in them) or anything. But that would be an example of *good* game design that helps mirror the envisioned game environment (i.e. where occasionally mechs just blow up), as opposed to just random, arbitrary mech hosing.