Startups are about ideas and ideas can come to anyone, anywhere and at no specific time, then you need to sit down, think, put things on papers and try to find the easiest way to get funded and run after endless number of VCs and prepare wonderful presentations and get rejected, then try again until you launch your company.
Before all these steps, you need a place to sit, think and write, and most of these “entrepreneurs” (I don’t really like this word anymore because of its misusage during the last couple of years) are with no money to invest in a nice prime location office with Herman Miller chairs.
So they end up in coffee shops, where most of their meetings and brainstorming are held with co-founders or even potential investors. Just by paying for a coffee, founders spend hours and hours in a relaxed and most of the time smoking-free environment.
I bet that not one single startup in this world, did not have at least 1 meeting or brainstorming session in a Starbucks shop and many of them are doing it at this very moment.
So Starbucks is the mother of all startups at their very early stage and all, for the price of a coffee cup.