I think it's really interesting that many of the responses to this thread include agreement that the culture the language is primarily attached to plays a huge role in the motivation to learn that language. It's something that I think is probably one of the main reasons behind many individuals choosing to learn less common languages (example: any Romance language.) Personally, the reason I've chosen to learn Korean and Japanese despite a vast majority claiming the languages are 'too hard' to learn for native English speakers is exactly that: I fell in love with the culture of South Korean and Japan, respectively. The fact that it's distinctly different from my own, with various nuances of the languages being directly influenced by the culture is just so interesting to me.
Everyone likely agrees that the language one choose to learn should have some significance to them, that it should be something they deeply care about in order to keep them motivated in their learning process. However, so many still continue to attempt to give one single language the distinguishing title of being the 'easiest language to learn.' The truth is: everyone learns language differently, so one person might be able to learn a given language easier than another individual. Many factors go into the learning process, like the individual's native tongue, and whether there is a lot of good quality material available for learning their target language. English may be one of the easier languages to learn in terms of material, since it's an in demand language for world wide business opportunities, but I personally wouldn't want to relearn English from scratch...and I speak it fluently.
Also, I've seen Esperanto being brought up, and I agree based on a linguistic perspective that it might be a good idea to begin learning Esperanto in order to segue into other language learning, particularly if you want to learn a Romance language. It's supposedly the most difficult to learn your first language (aside from your native tongue), and it gets easier thereafter; in theory, this is because you already have a basis on approaching a different grammar structure, etc.
That being said, I really just think that an individual should discover for themselves what is 'easy' and what isn't, and ignore all the articles that would tell them to stay clear of the language, because it's be too hard for them to learn. Think of how much you're limiting yourself by taking that approach. : (