WPTaven has a great article explaining the path that led to the decision have a simple option that will ‘restore’ the Old Editor when WordPress 5.0 is released.
This seems like a good solution that will help ease the pain for a lot of users. The WordPress Accessibility Team were especially active in this debate when it became clear that Gutenberg would not be fully accessible for launch:
What does this mean for most WP-ers?
The option to ‘disable’ Gutenberg using a plugin has been an option for a long time. This news just means that the ‘Classic Editor‘ will be bundled with WordPress 5.0 as standard. It’s a bit like when Tesla removed Ludicrous Mode from their cars by rolling out software which removed the option as the default.
And it’s true that the ‘Classic Editor’ approach is going to be the preferred choice for a LOT of people who have older or very complex websites that use incompatible systems (for example ones heavily reliant on Shortcodes). This isn’t a bad thing, it’s a practical and pragmatic solution to a complex issue.