That is a really brash statement. Usually this kind of comment comes from someone who hasn't really explored the advantages of the different languages they've tried, they've just taken every language that's come to them and manhandled it until it felt like the language they like. I've seen that happen before a lot, somebody likes C very much, so when they're introduced to Lisp, they basically write C in lisp. what does that give you? well for one thing, you have basically a program that is no better than the C version, but with a strange syntax. However, it means that the coder also hasn't taken advantage of the things you can do in lisp that are different from the things you can do in C. You can't write closures in C, so if you've only ever written in C you probably won't use them when writing in Lisp, and thus it seems like a pretty useless transition.
Languages ARE interfaces to the computer system, but that doesn't mean that some aren't more powerful than others. I could write a paper with a typewriter or a word processor, which are both viable ways to produce a document, but I can do things with a word processor that just aren't feasible on a typewriter. If you've never used a word processor, you won't miss things like "copy and paste" or being able to tweak your margins at any time, but if you HAVE used one before you will feel stifled without those abilities. Now, if you use a word processor, but you don't figure out how to use any of those handy features, than it's just an electronic typewriter to you and you'll say things like "tools don't matter! Typewriters and Word Processors are just two different ways to write a paper. That's it!"
of course, you'll probably get a few odd looks for saying that.