Sharavan, It is OK to have pets. It is also OK not to have any pets. For most people it is a personal choice. Islam does offer guidelines re pet ownership and you will find some literature which will not make many dog owners happy.
Yes some dogs have killed kids, and some cats can cause allergies or breathing problems. Most importantly I sincerely feel sorry that you were disrespected here in this forum. This is not the way of Muhammad SWS. He never humiliated a person. He always respected the seeker of knowledge and never made fun of a questioner. About pet ownership, we could have learned something more. Alas the state of Ummah!