He's kind of half-right, and the part he's right about is why I left the IT industry entirely. I just couldn't keep up, the skills churn was just too much and I couldn't devote enough time to learning the constant parade of new buzzwords just to continue to be able to do my job, while also having to do my job.
I knew quite a few people who were in various IT careers a few years ago, but have universally washed out and are now technical managers or in entirely different industries. The few who did stick around managed to do so because IT was both their career and hobby, and so they had home labs that were always running the latest-and-greatest of anything. Windows 8 was the straw that broke the camel's back, and I quit. Now I'm a technical manager too.
The industry moves too quickly, and requires a level of continuous retraining that's unlike anything else in existence. I'm not at all surprised it's better - for many reasons - to hire a new temp or employee than it is to retrain someone.