Language evolves and changes; 'tis the nature of the thing, and there's a sort of tiresome "Get off my lawn!" attitude that comes with people who get hugely upset by that change. Chaucer's English is barely recognizable as the same language as modern English -- words change meaning, are removed, added, morphed, mushed together, and torn apart all the time.
Definitely true, language is a living thing that shifts and evolves over time. However, it's one thing when a sensible change is introduced (e.g. new technology or social construct) that inspires a new word, but another when people are coming up with something just for the sake of sounding cool or being lazy. The latter is what gets me. While "chillax" is entertaining in a comedic venue, using it in real life just telegraphs "poser"...