Right now STWE is largely hamstrung by being DEX based for non-Alchs, and DEX is not a stat that's supported or synergistic with many classes. You need high DEX for STWE to be useful, but stacking DEX doesnt provide any benefit other than your thrown weapon DPS.
Brutal Throw lets you go STR based with throwers, but its also kinda useless since you cant make good use of throwers without STWE. Also it wouldn't be that necessary till late in Epic anyway, when to-hit becomes more of a concern.
I think an obvious solution to both shortcomings is to just link the two feats, so that both become useful together. Add the following effect to Brutal Throw:
You may use your STR, if it is higher, to determine your extra throw chance with Simple Thrown Weapons Expertise
That would open up a whole slew of possibilities for STR based throwers, getting an all-in-one stat for attack, damage, and extra shot, like Shuriken Monks and Vile Chemists enjoy, with a stat that will synergize better with many other features in mutiple classes.