During the course of the discussions, in fact, Evan You himself (the creator of Vue.js) commented with his thoughts.
People on both sides of what has shaped up to be a rather fierce debate are, of course, excited to see a new framework being included in Core, but the real question is which one, and why? Here are a few points brought up by people on either side regarding the two candidates:
- Has a (relatively speaking) higher learning curve, which might prove to be a barrier especially to new JS developers or WordPress developers adopting JS
- Licensing issues (particularly this one)
- Some WordPress contributors worry about so tightly linking WordPress to React, and by extension Facebook, a company whose ideology does not quite align with that of WordPress.
- Has an easier learning curve
- Is less widely adopted, and therefore some argue it has a smaller user community and a smaller maintenance community as well
- Obscuring JS with a template language is viewed by some as unfriendly to developers
- Having only a single main Vue.js maintainer is considered a danger. The Bus Test is, in summary, the ability of a project to withstand an important contributor abruptly leaving the project (for whatever reason).
There are of course many more points, which are neatly summarized in the linked summaries of the weekly JS chats. Additionally, many points are debatable. Licensing issues with React are seen as a nonissue by some, for example; JSX is seen as a similar hindrance when compared to templating; and Evan You points out that community maintainers mitigate some of the danger of Vue.js survivability.