This is very specific to the workflow of the developer. If you develop on a Windows Stack (through VMs) you very well could want the extra power to run the Visual Studio debugger. Or you may also want the extra power to run several Virtual machines. There are plenty of good reasons to get a high powered machines for web apps.
Having 100 chrome tabs open at once
No you quickly lose track of the "right" tab and then you're hunting through them all trying to figure out which one was most recently relevant. But I like that ability to open open open