We have to be careful when labeling vegetarians as acting against the Torah.
If someone believes that eating meat is fundamentally wrong because we have no moral authority to kill animals for our own needs when we can get adequate nutrition from other sources – I think that’s against the Torah.
If someone feels repulsed by the thought of eating meat because they picture the animals in their mind, but don’t see it as fundamentally wrong, I don’t think that’s against the Torah.
If someone feels that the practices of industrial meat production cause undue suffering to animals, unsanitary conditions, or even potential kashrus issues, I don’t think that’s against the Torah.
If someone wants to become a vegetarian for health reasons (e.g., following the Fuhrman diet), but doesn’t see eating meat as morally wrong, I don’t think that’s against the Torah.