You see, at least at first when mobile phones started to become popular, they all use Java or some other stricter language, heck, you can program Android apps in C++ if you wanted to (although I wouldn't recommend it). Now companies figure that they can just make a web app and it will be just the same as having a mobile app, they'll just have to go to the website to see it. This, although true, limits the possible jobs of all developers to mostly web monkey work, where you pay less attention on functionality and more attention on aesthetics, which some people may enjoy, but I sure don't.
Of course, I have no problem with them entering our industry, so long as they actually make an effort to learn good practices and choose a standard for their language. Otherwise you might be reading two JS projects from two different people, and the paradigms are so different you might think that's a whole different language! When I learn C++ I know that every C++ program will have essentially the same mentality to it.
I often get the impression that people who learn scripting languages are the same people who started off with game-makers because they didn't want to have to program the whole thing.
Of course, this is all a matter of opinion, I personally don't mind the essence of what scripting is, I just don't like the fact that it has basically no standards, and if it does, the language's interpreter doesn't enforce them (I believe the HTML & CSS are partly to blame for this, seeing that the browser often takes care of most errors your so lazy ass doesn't have to fix them). It's not the computer's (or in this case, the web browser's) to interpret what I mean (even though it is called an interpreter), its job is to read my code and if something is not standard or doesn't make sense, it doesn't fix it for me, it gives me a big fat error in bold red text that tells me "Hey, this code is shitty, you should change that!".