"why do they need to diversify into other brands?"

So Chipotle will enjoy continued growth for years to come and past performance is indicative of future results, guaranteed?

You had people on here after the e-coli scare just going on about how loyal people are and how this would blow over in a week or two. Several months later, they've given out millions of free burrito coupons and have to start a rewards program to push interest and the crowds thought to be loyal are not there. One can easily make a case that the restaurant was suffering from menu fatigue and the e-coli scare could have been handled better, but in any case, the last several months should be a very bold indicator of what kind of loyalty people really have when it comes to QSR's. How much of Chipotle's growth was a fad that now has cooled off considerably?

"Legions of customers have been steering clear of Chipotle after a series of food contamination scares made them wary of their burrito ritual. So many of them have stayed away, in fact, that chain saw a 29.7 percent plunge last quarter in sales at restaurants open more than 13 months — the sort of nosedive that is practically unheard of in the restaurant business.

Chipotle has been playing offense for months to try to win customers back, but in the past two weeks, those efforts have gone into a new phase: The chain added a new item to its famously tight menu, launched a summerlong rewards program and released a cutesy animated video that takes shots at its competitors." (https://www.washingtonpost.com/news/business/wp/2016/07/08/why-chipotles-challenges-may-go-beyond-food-safety/)

These sorts of growth stories do not grow to the stars and if mismanagement or various other problems come into play a growth story can turn quickly and it's not always easy to recover from. Why should anyone diversify their business? Why do anything? If Chipotle's growth story isn't over and the company has found such success with the core concept, why not expand upon it and offer additional concepts with a similar structure? If time passes and the fallout from the e-coli situation does not heal, then what? More rewards, more free burritos?

It's not unthinkable for a management team in this space to plan ahead for a future where the chain that brought the initial success does not have to do all the heavy lifting. In terms of overseas, whether expensive, high calorie/high sodium burritos are going to translate all over the world also remains to be seen.

It's bizarre to me the idea that diversification of a business where the customer can be extremely fickle (there's no loyalty, people will just go fucking eat somewhere else without a second thought) and tastes can change extremely quickly is such a horrible idea. There's maybe one or two CEOs in this space that I actually trust to do a skillful job navigating both the day-to-day and broader long-term changes in consumer trends and the only one that I continually reference is Howard Schultz.

"Why focus on other brands with worse economics, brands, and opportunity?"

So, nothing they will do will ever be as successful as the core concept? There's no need to ever prepare for the eventuality of a decline in growth, no need to ever try something new along the same lines? Okay. I guess they should also forget about the burger chain they're also apparently working on.