In my daily work I use Mathematica, and I like it very much. About 7-8 years ago, during first years of university, we were mainly using Maple for analytical derivations. Mathematica was considered to be better for numerics, since it was impossible for Maple to do them more or less fast. But nowadays (on my opinion), Mathematica is the best instrument to work with analytical stuff.
However, it is absolutely useless to write about "what I like", so I better describe things which I don't like, and which I hope will be changed soon. First I thought that it will be a little post with a list of disadvantages, but it looks like there is no way to make it short. So, there will be a few posts, and here is the first part - about the license.
In our relatively small and, in general, experimental institute we have about 20 online Mathematica licenses. In other words, twenty people can connect the server and perform calculations in the same time.
One of my roommates was doing quite extensive computations, often lasting several days. Sometimes his calculations were stopped during the night, because Mathematica suddenly decided to check the online license, and simply interrupted the ongoing evaluation before doing this.
Why are guys from Wolfram so agitated about the copyright? I guess I know the reason. For instance, in Russia one can buy a DVD with the last versions of Mathematica, Matlab, Mathcad, Origin Pro and other stuff (of total cost more than 10k Euro) for about 5 (yes, five) Euro. And people usually do. Furthermore, the illegal software is widely used for teaching in high schools and universities even nowadays. Hopefully, in Germany this is not the case.
Piracy is a problem. But do you really think that interrupting computations is the best way to attract new users?
The described above was actually the reason for my boss to buy me two home-licenses. But even activating home licenses is usually a pain in the neck, as mentioned in comment of BiophysicsMonkey to Chad's post, and I agree with it. Even updating licenses on both of my computers once a year is some kind of a problem I have to waste my time on, not to mention if you have a lot of machines as Chad does.
I'm completely ignorant in commercial software development, but I do not believe that there is no easier way to preserve the copyright.