Scope creep. It's really hard to say "no" to feature requests, especially if hundreds of people give it thumbs up, but it's a necessity if you want to keep your project from bloating over time.
Yeah I'm not saying it's a positive or negative change. Just an observation. Personally, I'd rename the next version to something else and let Vue be Vue, where Vue was founded as a replacement for the bloated SPA frameworks and super easy to just drop in and use.