Actually having both is a pretty nice. The reason is that it can be intimidating to someone in getting started. The notion of IDE via the web server is also useful for keeping the required software down on a machine you may not control. I was helping kids learn programming at a high school but the school would not give us permission to install putty[1] on the machines, using a browser based dev kit works well in this case.

Once you get someone past the basics and into the 'advanced' mode setting them up with ssh, vim, and screen is a great way to be productive on a linux machine.

[1] Putty in this case being the terminal emulator for PC's which can also talk to serial ports.