Removing tools removes unnecessary options.
Look at films. Scorsese, John Woo, Wes Anderson. The best cinematographic styles come from a reduced number of cameras, lenses and lights.
Being selective and curating your own toolbox makes decisions easier. You say, "I'll make this decision up-front so I don't have to think about it later." It's a type of minimalism.
Your remaining decisions become clearer. You focus on more important things like the angle, the subject and the message.
With startups it's the same. Pick a toolset: Mailchimp, Slack, AngularJS, PHP. Then when you roll out, you're not scrambling. Decisions about marketing, product, and deployment are focused around what actually matters.
When you have to think fast, you can hone in on the opportunity at hand.
Inspired by filmmakers Nicholas Corcorran and Jim Denault
Image credits: Tony Hall and Daren