As apo mentioned above, I also agree that electronic communication and the internet these days may have influenced the way we use language a great deal.
I myself do not have a highly sophisticated English vocabulary/lexicon, but I am still able to write coherently, influence others, and use proper grammar and all using whatever limited amount of words that I know even though I don't know a lot. So, the vocabulary thing doesn't really bother me.
And just because someone may know a greater number of words doesn't necessarily mean that he or she is more intelligent than a person who knows a lesser number of words. Language is not all about how many words you know.
I myself do not have a highly sophisticated English vocabulary/lexicon, but I am still able to write coherently, influence others, and use proper grammar and all using whatever limited amount of words that I know even though I don't know a lot. So, the vocabulary thing doesn't really bother me.
And just because someone may know a greater number of words doesn't necessarily mean that he or she is more intelligent than a person who knows a lesser number of words. Language is not all about how many words you know.