It's the other way around!
If you just find out your father is a gambler addict, as addiction takes time and you're surprised then it simply means you didn't care much about him in the first place as you never saw the obvious signs out there, gambling addicts are going to leave obvious signs around them, tickets, spending time in gambling locations, money missing, talks about gambling, bragging about it, etc etc.
So rather than losing respect better ask yourself why you missed it, just like those parents that find out after 5 years their son is a junkie!