Any good reason for using lightning component
It really depends on your business Scenario of what you are trying to achieve and your UX approach and design decisions .If you want your users to completely align to standard lightning experience going lightning components route will benefit them in long term
If you are in ISV space ,then you want to try and use lightning component framework to provide end users(Your end users are other salesforce orgs where your apps are installed) flexibility to use the builders that salesforce out of box provides .
Building with React or Angular will imply admins or business consultants wont be able to configure or control the layout .Lets say you provide that ability then you are rebuilding the builders that salesforce has already built for you .
Salesforce is trying to provide a framework that does handle lot of things for you OOB .Lightning Action Services are great step towards that where salesforce will be providing a single tag that handles CRUD respecting org CRUD/FLS and sharing configurations.
In angular or React you are simply rebuilding lot of stuff that platform automatically gives in lightning component framework (Examples include Internationalisation , labels, Locale Date formats etc).
If you ask me as of today (22nd oct 2016) its lot better than how it was an year ago and its keep getting better and better .The base components ,Utility bars ,Quick actions , Lightning Out ,Added Interfaces all are pretty robust now to build a functional apps .While there are few gaps being a new technology with a learning curve and not much libraries available open source compatible its an extra pain which i am sure with time it will be sorted .So if you are thinking of future and planning to use salesforce wont be bad idea to go with lightning component framework and If you feel you are invested in SFDC for short term then frameworks like angular or react makes sense as that can be used with any other Technology Stack .
My .02 for what it's worth...
I've never liked Visualforce development. It always felt like either I was wrestling with it to do what I wanted, or that I was faced with using it just as a wrapper for something based on Javascript, React, etc (which I don't know). And if I was going to use it just as a wrapper, I'd rather let dedicated UI and presentation folks write that part and just use APIs I'd write to pass data back and forth.
At Dreamforce 2015, there was a major push for Lightning but it was all new to me. It was overwhelming because I'm not a HTML, CSS, Javascript, etc, person and I didn't see any mature examples of what Lightning Components could do. At Dreamforce 2016, I attended nothing but Lightning sessions so I could wrap my head around what this thing is, and this year could see more mature examples of how everything worked. Everything "clicked" for me.
Now, I've started playing around with it and even though I don't have HTML, CSS, or Javascript skills, I'm slowly starting to figure things out and so far I really like it, and am taking baby steps piecing some components together to see what they can do.
One thing that's a major factor for me is that I work at a small startup and my main customer is a Support team made up of only 4 people, and I have a really good understanding of their workflows. They've been using a Service Cloud console up until now, and while it's usable, they could be a lot more efficient with a custom case management system.
I would never have tackled such a thing with Visualforce (either native or as a wrapper) but with Lightning, I'm really feeling like we can develop exactly what we need, use native Salesforce technologies, and explore mobile options for case management down the road.
Maybe frameworks like React, etc, are better in some way, but I wouldn't know because I don't know those frameworks. But just in my short time working with Lightning, my gut instinct is that it just "feels" right. I can learn it, make it do what I want, and develop a great solution using it for our Support team.
And from a maintenance aspect, there's a lot of appeal for using native Salesforce technologies because down the road if we hire additional Salesforce developers, we don't have to worry so much about finding people skilled in both Salesforce and React/etc, but can concentrate on finding somebody really good at Salesfroce development in general and they could probably pick up on Lightning pretty quickly if they don't already know it (like I am today).