The vegetarian part? Vegetarianism is good for the health. Too many people eat too much meat.
I am not imposing vegetarianism on people who chose to be Sikhs. I studied Raag Malaar pg 1289 and 1290. "Maas maas murkeh jhagla" People drink milk but do not eat eggs. Hindus forbid meat but allow milk because it comes from the mother cow goddess. Many so called Sikhs are imposing this custom to Sikhs that they cannot eat eggs but can drink milk. Then I guess we shouldn't eat fruit because we kill the produce or cause the plants pain. It is proven that vibrations and voice patterns, good or calming affect plant growth. Plant life is just as a vital part of the world as humans are. Sikhs respect all forms of life but refrain from Sanyasism to avoid extremisms.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/new-to-sikhism/30539-can-you-tell-how-become-sikh.html
Sikhs are not allowed to eat Halal, and if they have to eat meat, it should be jhatka. Everything is maas, we marry and join to maas, we are born maas, we die maas.