> All human languages have very similar every day vocabularies

I spent a lot of time working in Sweden and had many conversations with the locals (all of whom know English very well). Many of them remarked that English has more alternative words for something than Swedish and that each one has a subtly different meaning. For example, how you can use "grand" in place of "big" or "large", they all mean roughly the same thing but "grand" brings with it additional meaning. So, my personal experience appears to contradict this statement.

My point is really that languages and alphabets are tools and some tools make certain jobs easier. You could write a website in assembly, but its easier in Rails. However, I suspect our ancestors will look back at Rails and have similar feelings to us when we look back at ancient writing systems now.