Oh please. You have no idea the hell you have brought upon yourself.
They have never steered me wrong. There are projects they have loved and said, "I would love to see it when you're finished. I would love to test it out!" There are also other projects where: "It's not worth it to work on that." "I don't really see that as a demand or useful to anyone but you."
99% of the time they are giving me solid and sound advice. I think the 1% that remains is: Miscommunication. They misunderstand what I am after or I just didn't explain it right.
As to answer the original question: Honestly, if my code is that good... awesome. But I likely got that code from some sample library that can be found anywhere on the Internet. If the code is good and it helps someone out, than why not? I've tried to view source on sites for something cool that someone's website was doing. Sometimes I can get the script, but often times, it is usually a combination of javascript and some PHP scripts working together, so it is not always easy to just grab the code.
If more substantial parts of our apps were client side, like if we sold an online image editor, I would be very afraid.
However I have doubts as to how much more vulnerable to copying JS is than anything else. People have been pirating compiled apps just as long and they don't seem any less prolific
And if your code really is that good and so unique that someone might want to steal it, perhaps you should try to extract it and product-ify it. Possibly as an open source project.
I don't think it's something to worry about. Someone that is smart enough to steal and use your code is smart enough to use a legal alternative.
I'm more concerned with competitors copying designs, and witty UX concepts than actual JS code. This you can put obstacles in front of by making some things only available post-purchase, or by "demo only" if the customer is undecided.