There was a time when it seemed like a good idea. Did it myself. Not sure it's such a good idea today.
It's easy to be blame others for their actions. What's been happening for quite some time is that the yields have become so low that to get any kind of return one needs to invest in stocks. The government or Fed with such low rates has brought about this shift. Those who are retired or on fixed income are suffering the most due to this. It could also be that we may have have more juice in the market and the early birds might get a decent return. It's not the run up that's a problem, it's the end of that run up. That's when the naked swimmers are identified. Gringo
you don't have to choose between stocks, which may go down, and bonds which will surely go down. You can always go to cash, which with low inflation will at least protect what you made with only a small loss. Nothing has changed, over time the best bet has always been buying businesses in the form of stocks. But back then you could get 6 or even 10% (sometimes tax free) in fixed income. Those days are gone and I don't have much sympathy for those old savers that didn't diversify.