In my campaign, getting raised from the dead is expensive and difficult. I've also imposed a stronger penalty on those actually casting the spells to raise the dead...I've made it more taxing on them.
Lastly, I only allow a character to be raised once, and with the knowledge that being raised from the dead makes them a bit of an aberration (even to the point of some religions frowning upon it). I'm allowing a single raise, because not allowing at least one would be a little harsh. I WANT them to continue playing the same character. They've developed a history with the character, and their background is familiar to them. But, being adventurers, they are certainly not immune to death and tragedy (otherwise, more people would adventure). I want them to have a fear of death. If the character dies once, you can bet the player will be more cautious...