I personally prefer PC.
I hate Valve, Microsoft and Sony. They all use dirty, cheap tactics to get more cash. I'd say valve is the worst for it. Why you might ask? Well lets take CS:GO for example. Are valve taking measures to stop hackers and smurfers? No. Why not? Because these people buy new copies of the game meaning they get extra dolla dolla. They could easily stop hackers. Hacking can be as easy as injecting a .dll file into the games process which is easy to stop but valve want the hackers to get banned buy a new account etc. etc.
All of them are as bad as each other. Play the one you prefer.
Preventing people from hacking isn't the easiest thing to accomplish. This is why most online games have security systems in place to catch them and ban them. I don't know of any system that actually entirely prevents it from happening. You can try, but hackers will always find a way around it.
Personally, Valve is my favorite game company simply because they tend to do things right by the customer as best as they can. As for them making money off people who decide to buy the game again after being banned .. there is nothing wrong with that. How do you suppose they prevent someone from buying the game again? Stalk them?
Point is, that is a very unreasonable reason to say you hate Valve lol. You can come up with something better, but it's hard to since Valve rarly does things wrong. Their latest blunder was with Bethesda and the paid mods fiasco. However, even then it's not like the idea of paid mods itself is bad, it just was the game they where doing it to.