Does WELS have any opinions on vegetarians/vegans? I see it as a way to help God's earth and minimize suffering. Why are people often so quick to try to invalidate those views?
Your question deals with a subject matter that God has neither commanded nor forbidden. Romans 14:1-8 makes clear that dietary preferences lie in the realm of Christian freedom. That means that people are to refrain from condemning another person’s exercise of Christian freedom (Colossians 2:16).
In Christian freedom and with godly attitudes, God’s children can glorify him even in the daily routines of eating and drinking (Romans 14:6; 1 Corinthians 10:31).
The apostle Paul put disputes over dietary preferences in perspective when he wrote, “For the kingdom of God is not a matter of eating and drinking, but of righteousness, peace and joy in the Holy Spirit” (Romans 14:17).