Yes, I think it is excellent for people to remarry. In the case of death and divorce, there can be a lot of hurt. With divorce, specifically, relationships may have been unhealthy or lacking in one area or another. A subsequent marriage provides a fresh start with a potentially healthier relationship. When the death of a spouse occurs, I do not see it fair to the widowed spouse to be forced to remain alone following said death. One of the basic human needs is love; marriage, when taken seriously, meets this need of love, even if it is not the first time.
Yes, I think it's good for people to remarry, because humans are social creatures by their natures. That means that we are not meant to be alone. It is good for people to remarry because they can have companionship. People who are remarried have been shown to live longer because they are not alone.
Some remarriages are very good for people, especially after a loved one dies, a new marriage sometimes helps people start living again and get over the mourning process. While true, there are people who are on their 8th and 9th marriage, and you have to wonder, what's the point? Regardless, people should be able to do whatever the want to in terms of marriage and that's good in itself.
I believe it is a bad thing for people to remarry multiple times. I've met many people who have been through three and four marriages and I just think that defeats the purpose. I think a person that has had that many failed marriages should come to realize that marriage simply is not for them.