So you don't like the idea of running programs inside the web browser. Big whoop. It's the chosen runtime for the work of this group for exactly one reason: it has managed to achieve a ubiquity that no other platform has succeeded at doing—not even those that made it an explicit goal.
What's more, if you set out to oppose triple scripts on those grounds, you will (a) have missed the point—since triplescripts.org is about the goal that you should be able to run scripts even if all you have is a Web browser, and not that you have to (or even should) actually run them that way (see invariants; it is a core tenet that triple scripts work from the command-line, too)—and (b) you will almost certainly contradict yourself sometime in the not too distant future, maybe even by the end of the day or in the next hour, because you're probably already using tons of software that works in the browser (this wiki is one example), whether you like it or not.
Let's direct the unstoppable, ever-expanding scope of browsers towards something worthwhile. The triplescripts.org group's pursuit of zero-setup metatooling is worthwhile.