A ruler not loved by the people is not legitimate.
I guess it depends on if all of the population governed by said ruler would fall under either category, but generally it is the ethical hope that more positive incentive in free societies would surround the ruler that is instated, but of course this would vary from country to country.
Think of it this way: if a captive loves his or her captor, what reason do they have to disobey or seek freedom? A leader who is loved can much more easily control his populace, who are eager to do his bidding to prove their love for them. Those leaders who rule with fear are often not only feared, but regarded with contempt. Eventually, the people will tire of their captivity in fear and yearn for freedom, eventually over-throwing the tyrant.
A ruler shouldn't be completely loved by everyone. If they are, they are not sticking with their own opinions. Everyone's opinions are different, and when somebody doesn't agree with the ruler, they will not love the ruler. A ruler should be at least a little bit feared to put his/her followers in order. If the ruler is not feared, the followers will essentially be people called followers, but they won't actually follow the ruler.
" A ruler must aspire to be both loved and feared , and where it is so difficult to have both merits in one person , then it is much safer to be feared than to be loved " Niccolo Machiavelli -The Prince-