Here's how  I see it.

There's machine code and it's all that computers needs in order to run something. Computers don't care about programming languages. It doesn't matter to them whether the machine code comes from Perl, Python or PHP. Programming languages don't serve computers. They serve programmers.

Some programming languages run slower than others but that's not necessarily because there is something wrong with them. In many cases, it's because they do more things that programmers would otherwise have to do (i.e. memory management) and by doing these things, they are better in what they are supposed to do - serve programmers.

So, is slower performance, of programming languages, really, a bad thing?

I don't think it's automatically bad. Python is slower than C++, but when both are fast enough, Python may be the best choice for the problem at hand even if it's slower.

It's always a tradeoff. For small one-off tasks, it's much faster to write a Python script than a C++ app that does the same (the typical example for me would be some kind of batch text processing or walking a directory tree and doing something to the files), and I don't really care whether it takes 10 ms or 1000 ms, even though it's 100x slower, because it may take me half the time to write and test.

Of course, it would be nice if Python was as fast as C++, so in that sense I agree with your statement that "slow = bad". But then I rather have a powerful language that runs as fast as I want by not doing some things (say, array bounds checking on raw arrays) as long as it allows me to decide when to make that tradeoff (say, by using std::vector).
