You should choose this type of service because Dedicated Server Hosting offers you the opportunity to rent an entire server with on-location technical support. You can customize the server as you want. You should select dedicated server hosting if your web site requires customized options or your web site needs dedicated resources due to the high amount of traffic.
The reason why you shouldn't choose this type of web hosting is because dedicated server hosting is powerful, yet expensive. You should not get dedicated server hosting if your sites don't require huge resources or if your budget will not allow for the expense at this time.