Oh.. I didn't make the connection. Honestly, I looked at the bootypedia and did not pay much attention to it. HE/Frag Grenades, Satchel charge, Prox, WP and IED are all things I glanced at and dismissed.
HE/Frag are either easy enough to replace with a black powder bomb (seeing the effect immediately is really strong compared to waiting and risking your target surviving and blowing you up on their turn, plus being manufacturable for cheap), and the HE can be looted easily (I have more than I know what to do with, since I still mostly use BPB. I am switching now, since a pre-primed HE is faster to use, I have lots and I am starting to know the enemy better).
Satchel, proxies and IED fall in the too expensive again (HE and then dynamite are good enough to blow cyberdiscs or tanks).
WP.. I'm not sure.. If I use a trap, I'd rather something that kills/maim so hopefully the enemy is taken out or hurt enough to not be too dangerous. Explosives (proxies/IED are sure to explode at ground zero by the very way they work) are likely to do that, setting on fire doesn't. Once you add morale damage to the WP's fire damage (and maybe some instant damage from the pyrotechnics?) it will become interesting, since setting something on fire is likely to panic them = take them out of the fight.