Depends on what you know and what qualities you have. If knowledge and skills aren't reliable, then it's better to hold. If you still know something, you can earn much more than just holding for long time...
Yeah, knowledge does play an important role in any decision one is making and that makes it pretty interesting if you have the knowledge of long term trading. Holding may not sound like a smart job to many traders as they do believe into active trading. But who is making more profits in a given time may decide about the real smartness.
I am a holder and at the same time a long term trader who usually take advantage of behaving more like the institutions by buying during accumulation and selling during distribution. You cannot miss it as long as you know what you are doing and you are making good use of every moment to increase your portfolio than just holding it all through.