The 'glass transmission' is a myth started by a few new Subaru owners that thought they should be able to side-step their clutch like they did in their previous Honduhs. It all depends on the driver. I sold my Forester with 126k on it and no problems, but I could also launch it with all four wheels spinning at least a few times a month. Because I knew what I was doing. Original clutch, original gears.
On the other hand (and to your point), I wouldn't have let just anyone drive my Forester. You have to respect the fact that with AWD, all four wheels grip and so the weakest point in a bad/shocking launch may be the gears/axles/etc instead of the tires losing traction.
Anyhow, just saying Subaru transmissions aren't junk.
OP, too bad to hear you couldn't keep up. I'm planning to go Stage 1 in my GTI because I miss the power way too much, but I don't really want to do more than that. I guess I'll just have to be satisfied that a modified Subie will always pull on me!