That is the question. Over the years, I have heard varying opinions from home inspectors regarding whether the home should have gutters. The two primary functions they talk about are to prevent water penetration into the basement and keep water from the entrances and walkways.
Some say it is an essential function of the house to keep the water away from the foundation. Others say proper grading by pitching the soil away from the foundation and moving plantings a foot or so away from the house will accomplish a similar effect. Regardless of their opinion of the need for gutters, they all agree that proper grading and keeping plantings away from the home is necessary.
The one varying opinion primarily relates to the type of roof. If a roof is made of metal or slate, there is potential for the gutters to be ripped off with severe weather. Heavy snow and ice can slide off these types of roofs and pull the gutters off with force. For that reason, many inspectors say it may not be wise or necessary to have gutters on the house.
If you have gutters or want to install or replace your gutters, you may want to consider the type with a shield on the top that will let water in, but not debris like leave and pine needles. Without covers, it is easy for debris to collect and fill the gutters so that they don't function as they were designed. Keeping them clean and clear is essential.
Another reason for considering gutters with some type of cover is getting up on a ladder to clean them can be dangerous, especially if the gutters are on the second story - Always use caution when cleaning gutters - Safety first.