I lucked out on a lot of strong units and I prefer this system, I could easily have been unlucky and the amount of indirect cooperation from others in this game is a welcome change from just plan ol desperation. Especially since I can use about half of the good characters I've rolled at any one time anyway. Makes me feel helpful if people get good use out of them.
Yeah, exactly this. I love the system too.
While you always want to personally pull your favorite characters so they can be in your own roster, the beauty about F/GO is that, if you don't manage to have luck in that area, you can still join up with your friends and bring their character into your party to help you. On the reverse, if you manage to pull the character while they didn't, you help them. I'd much rather it this way than needing to have the character as your own, especially in a game with as many Servants as there are (with limited-time ones being added into the mix), even moreso when factor in the lower rate of chance to get them.
Basically, using the Friend List isn't "abusing" the game, it's making use of one of its features. It's meant to be helpful for this very reason, otherwise people wouldn't need to befriend each other. If anyone needs to bring in a powerful friend to make a certain quest easier and/or faster, all the more reason to do it!