Easy to Get Started With
Ruby was originally designed with the goal of making programming fun, and in Japan, where it came from, Ruby was used to make games. Ruby is succinct and reads like English, which makes the code easy to understand for coding beginners.
Since you'll be able to build prototypes quickly with Ruby on Rails, many find coding in Ruby a satisfying experience.
As a dynamically typed language, Ruby does not have hard rules on how to build features, and it is very close to spoken languages. You'll have more flexibility solving problems using different methods. Furthermore, Ruby is also more forgiving of errors, so you'll still be able to compile and run your program until you hit the problematic part.
Not Easy to Maintain
Because Ruby is a dynamically typed language, the same thing can easily mean something different depending on the context. As a Ruby app grows larger and more complex, this may get difficult to maintain as errors will become difficult to track down and fix, so it will take experience and insight to know how to design your code or write unit tests to ease maintainability. However, you can learn how to design code better by working with an experienced Ruby mentor.
As a dynamically typed language, Ruby is slow because it is too flexible and the machine would need to do a lot of referencing to make sure what the definition of something is, and this slows Ruby performance down. Rails is in general more resource-hungry as well.
At any rate, there are alternatives such as JRuby, which is a faster implementation of Ruby. While this is probably still not as fast as Java, for example, it's still a vast improvement.
First of all, community size is important, because the larger a programming language community is, the more support you'd be likely to get. As you step into the programming world, you'll soon understand how vital support is, as the developer community is all about giving and receiving help. Moreover, the larger a community, the more people will be building useful tools to make development in that particular language easier. As of now, there are over 600 notable programming languages world-wide.
So, with that context in mind, let's get into the details of the Ruby community size.
8th Largest StackOverflow Community
StackOverflow is a programming Q&A site you will no doubt become intimate with as a coding beginner. In terms of programming languages, Ruby has over 27k followers, making it the 9th most followed language. Ruby in general is a community that is quite welcoming to beginners, and out of popular languages Ruby questions are the 2nd most likely to be answered.
5th Largest Meetup Community
At meetups, you can generally network and learn from fellow developers. Meetups often offer mentorship to those who want it as well. There are over 840 Ruby groups at Meetup.com, totaling over 430k members worldwide.
In terms of MVC web frameworks, Ruby on Rails is still by far the most popular web framework, and with the majority of the community so concentrated on one framework, you'd get far more support on the Rails framework when compared to the fragmented framework ecosystem of other programming languages.
3rd most tagged language at GitHub
Generally, the more useful projects there are, the more likely someone has already built a function you need and built it well, which will greatly speed up your development process. Ruby on Rails is known to have many nice gems and tools that helps with development, and there are over 970 Ruby projects on GitHub that have over 500 stars.
Salary information from gooroo.io
Startup businesses are a huge thing, and there's plenty of opportunity as a Ruby developer - it is the 4th most demanded programming skill on Angel List. Startups in general are also more open to hiring non-computer science majors onto their development team as long as you have proved yourself worthy.
With the rise of Node.js, Ruby on Rails' popularity has diminished somewhat, but thanks to the ease of prototyping with Ruby on Rails, tech startups continue to love Ruby on Rails.
Ruby is the 10th most popular language on the TIOBE index
As an open source project, Rails is actively worked on with a relatively fast update cycle, and Ruby on Rails 5 beta version was just recently released on December 18th, thus Ruby's ability to stay technically relevant is still strong.
Interest in learning Ruby grew 22.2% in 2015
As a programming language's ability to stay relevant also depends on whether the language is getting new blood, it's clear Ruby is still growing pretty steadily.
Ruby remains 2015's most-taught programming language by coding bootcamps because aspiring web developers can easily get started with it. Considering the estimated growth rate of bootcamps being at 138%, one could expect Ruby to have a relatively steady inflow of newcomers to keep the community alive.