It's difficult and takes practice, but in today's game alot of times you need both.  Most of the people that say that the "ball hooks too much" can do something either with hand position, ball speed and/or loft to help deal with these issues. And in most of those cases, they bought a ball that was too aggressive to begin with.  I have and use 4 different hand positions and the ability to use them depends on the ball and the layout. You're still at the mercy of the bowling ball and the layout to a large extent.

For example, I just bought a Bedlam and put a pin over ring finger, cg out drill on it.  It doesn't matter how much hand I take out of it, it skids in oil and goes left in a hurry off of friction. I can tweak the ball reaction with hand position, but this ball is meant to cross boards and does it really well, especially when they break down a little bit. But try to play straight with it and it's a little touchy.  

Even now, to be an elite tournament player, you have to be able to use different hand positions, play different parts of the lane as well as make the correct ball choice.  Sure, you can succeed in league play in most centers by standing left and flinging the ball right with as much speed and revolutions you can put on it.  Put that guy on any PBA pattern and in most cases, he'll be humbled in a hurry.  

The people that come on these sites and brag about the "good old days" need a reality check.  Ball Selection is a part of the game today, no matter how "good" you are.  You can't outbowl a bad ball reaction no matter how good you are or how many hand positions you use.  You want integrity, bowl a PBA experience league and bowl tournaments that don't put down a "China" shot.  But don't bowl in your recreational league with a "China Shot" and complain that the sport lacks integrity when YOU are not willing to take on the challenges of a tougher shot.