You have to decide what line of business you are in:
1. Are you making games to sell to honest people?
2. Are you making free puzzle games for crackers?
You also need to decide if your game is aimed at hardcore gamers or more casual gamers. Hardcore gamers will put up with all sorts of copy protection annoyances to play a game.They be happy to reboot with a special configuration that excludes the drivers they need to get work done (like a virtual CD driver or a macro program), allow special "protection/license" services to run even when they aren't playing the game, etc. But the more of that crap there is, the less likely a more casual gamer is to buy and play the game.
I'm a very casual gamer. I can only squeeze in a few hours a week max for playing games. Before I buy a game, I try to carefully research it to be sure it:
a) installs completely on my hard drive.
I don't want to have to hunt up and insert the CD when I have time to play. If the game wants the CD inserted just to prove I bought the game (and will not work easily with Game Jackal), I don't buy it. After all, people who don't buy the game but get a cracked version off the net don't have to keep the CD handy, so why should those of us who pay for the game to have to do so? (Quizzes requiring the manual are even worse.)
b) does not keep anything running on my system when I am not playing the game.
Sorry. Your protection services do not need to be always running and eating eating my memory and my CPU cycles. Start them with the game and stop them (and remove them from memory) immediately when I exit the game.
c) works with whatever drivers and always on software I want to use.
I need a virtual CD for work. It's not coming off to play a game just to make copy protection happy. The same with macro programs, VMware network drivers and the like. If I have to reboot in some special configuration to make the copy protection happy, I'm not buying the game.
d) has NO rootkits or other hidden crap
that could mess over my system and not even leave me a clue it is running.
e) uninstalls ALL copy protection when I uninstall the game.
f) does not need to "call home" to allow me to play
Hardcore gamers will put up with all this and more, of course. Those of us who squeeze in a few hours a week for games generally will not. I admit I'm more strict than a lot of people, but the more hoops the copy protection makes people jump through to play, the less likely more casual gamers are to buy the game.