More seriously, I'd turn the question around. BASE requires you to think hard about a lot of things that ACID gives you for free. The benefits are better performance and scalability. But if you're not certain you need that performance, why go through the extra trouble?
(That said, it also depends of the data model. If you're certain your data is key/value without any relationships and will always be key/value, a key/value store is likely appropriate. If you have something more complex, I don't see it.)
More seriously, I'd turn the question around. BASE requires you to think hard about a lot of things that ACID gives you for free. The benefits are better performance and scalability. But if you're not certain you need that performance, why go through the extra trouble?
(That said, it also depends of the data model. If you're certain your data is key/value without any relationships and will always be key/value, a key/value store is likely appropriate. If you have something more complex, I don't see it.)