The difference is Steve Jobs spent 10 years working on NeXT, developing a clearer vision of the PC and creating what became OSX. Jack Dorsey spent 5 years doing POS systems and credit card processing deals at Square. Twitter isn't lacking for a "Twitter Pay" feature.
Dorsey's original idea for Twttr was a service that let you group SMS what club you're at to your friends list. If he had been on his own it probably would have been yet another group texting app (maybe eventually WhatsApp). It was Evan Williams (IMHO), with his Blogger experience, that developed Twitter into the "micro blogging" service we came to know. Evan Williams is working on Medium now, another idea broadcasting platform.
Is Square that much of a failure? I've always had a positive impression of it, and a lot of small merchants in my city use it and seem to like it (or so I thought).
Actually, that might not be as silly as it sounds... What if Twitter tried to pivot into something like Patreon? They already have one of the world's largest social graphs of followers and creators; just add a payment layer and things could get quite interesting.
"Twitter users create the favorite and just like they own their tweets they should own the result of their action. If you favorite something we argue that you should be able to decide what you want to do with the data you create. If you want to use it to give Flattr donations to other Twitter users you should be the one to make that decision."
Dorsey's original idea for Twttr was a service that let you group SMS what club you're at to your friends list. If he had been on his own it probably would have been yet another group texting app (maybe eventually WhatsApp). It was Evan Williams (IMHO), with his Blogger experience, that developed Twitter into the "micro blogging" service we came to know. Evan Williams is working on Medium now, another idea broadcasting platform.