You quite clearly have no understanding of how social media works. It’s an inverse business model where the customers are also your content creators. In the case of Twitter you have celebrities, sports stars, journalists, musicians, brands, news networks, the list goes on, creating content for free and engaging with these customers to create more content and in return advertisers were desperate to sandwich their adverts in-between this content.
To introduce a pay gate in the middle of that and remove the security that was in place for the most important of these content creators was mindlessly stupid.
See Marques Brownlee’s Tweet above. What he could possibly have done was develop and release a new set of features which enhance the product and paywall those.