The OP doesn't understand how stocks work. Let me ask you this? If you had held a company like MCD from 30 years ago, how much money would you have made? 100% or 8000%? The charts are only part of the story. Most companies do splits, and give dividends. That's where the real money is for a longer term strategy. I'm surprised seeking alpha would do such an ignorant article.
So much talk about the dividends, charts, etc. Look at the numbers. I posted the Total returns, which include dividends as well as a link to the source. The SP500 LOST money over the past 10 years, and that is WITH dividends, and NOT accounting for taxes on those dividends.
I hate to belabor this point as it has been pointed out numerous times by others, but apparently it needs to be restated: Whether you come out ahead or behind depends on which ten year period you select. As the length of the time period becomes shorter, the outcome becomes more dependent on which specific period is selected, and conversely, as the time period grows longer, the outcome becomes less dependent on the particular period selected. I believe for any twenty year period (that is what I recall, i could be mistaken) the outcome is positive regardless of which 20-year period you select. However, as I wrote above, the important number is the total return in constant dollars. When expressed that way, there may even be a 20-year periods where the total return is negative, especially if you omit dividends.
The last five years I average 10%. Before I had no exposure....most investors, I mean the serious money use some kind of a timing system. Only the idiots are buy and hold. Even the old timers like Buffett sell stuff and buy on dips.