It is a good enough reason. Any sort of demands from either side should be.

If a guy asks for dowry doesn't that mean he's(or his parents) looking at the relationship as a business transaction and may ask for more money in future ?

This gives me the feeling that you think only guys do this. How many parents will even consider a guy if he doesn't have a job? I have had cases where the girls side told me they considered me because I had my current job, and if I had my earlier job, they would have rejected me. I had a girl tell me she agreed for the marriage because she thought she could do x things after marriage (which would have put a heavy financial burden on me-idiot me didn't think through all of that when I agreed, and luckily this conversation ended that proposal).

As long as the woman is working, and would never be dependent on the guy financially, dowry shouldn't exist. But when I have to provide for her and take care of her parents, and when they won't hesitate to squeeze every last drop of divorce dowry (alimony) from me, I am not quite so sure.