But the bulk of your argument is misinformed, and the rest of it stupid.
About 75% of soy is used for animal feed.
Much of the rest is in biofuels, as well as cooking oils, salad dressings, chocolate, baked goods and other foodstuffs.
Only about 7% is used for what you might call "vegan" foods, like tofu, tempeh, edamame and miso - but the vast majority of people who regularly eat those foods aren't vegan.
So you're magnitudes off with your numbers.
If everyone in the world (A) went vegan tomorrow, and (B) replaced every single meat item in their diet with tofu, that would result in about a 60-70% drop in soybean agriculture. It takes 50 to 100 times as much land to produce a kilocalorie of beef or lamb versus plant-based alternatives.
I doubt any vegans actually substitute tofu for mear on a 1:1 basis but, even if they did, they would be reducing their "soybean footrpint" by somewhere in the region of 75-95% (depending on the types of meat they previously ate).
If your "point" is that vegans still have some residual "soybean footrpint", that's incredibly specious.
If someone told you that, through finding alternative products/services, they'd managed to reduce their monthly outgoings by ~80%, "lol, you still spend some money so you shouldn't have bothered" would be a ridiculous position - and its basically yours, here.
Incidentally, I'm not vegan, but I find some of the arguments advanced against veganism to be embarrassingly empty-headed, and more rooted in insecurity in personal choice to eat meat than anything else.