First, don’t listen to anti-catholic propoganda…that is silly.
My understanding of patron saints is that these saints, for some particular reason, have been associated with particular things because of what they did in life. For example, St. Francis is known to have preached to animals. Now we call him the patron saint of animals (among other things) because we know he has had experience in dealings with animals and can help us with our own issues. That doesn’t mean that some other saint cannot intercede on our behalf with it comes to things like this, but we know for a fact that St. Francis has the particular experience and grace required to help with this type of thing.
Take a different example from life on earth. Sometimes, if I need help with work related issues, I will talk to my wife. I know she has a great work ethic and experience…so naturally I turn to her when I need advice or guidance. The same is true for my friend, who I go to when I am having computer issues. He has the experience and talent needed for that area. In the same way, we ask our friends in heaven to help us with the things we already know they are good at.
We can pray to St. Raphael for healing, for we know God has given him the grace and power to heal in the past. We hope He will do this in the future!
We can pray to St. Mary for purity. We know that she was a virgin, and can help us with our struggles and temptations there…because we know she has already conquered this virtue, by the grace of God!
Patron saints of certain actions/professions/items are there to help guide us to the people we need to get the help where we need it.

You can call them specialists if that helps.