Maybe not so much meat but, protein. You don't need to eat meat to get protein. I don't know a hell of a lot about Mike Mahler but, I'm sure he needs to make a conscious effort to get a good amount of protein and fat in each meal.
When meat/animal products (we are talking vegans here) is an option this is much easier. When it's not an option it can still be done.
The issue with the stereo typed vegan is the crappy information they preach about the alleged dangers of eating meat/animal products.
I actually have respect for people who are vegans/vegetarions/whatevers for ethical reasons - I don't know how anyone can argue with that. They have a 'belief' and they make a stance.
On top of that - I'm pretty sure the majority of vegans aren't bodybuilders let alone strong. Mike Mahler is the exception rather than the norm. I've never seen a vegan in real life that I didn't feel sorry for.
Lastly. Meat tastes good
. I don't think you have people here saying you need to eat meat to be strong. You just have some proud meat eaters, just like you get proud vegans.