Is Longer Better? (don't say "of course" just yet..)

It is a difficult task in convincing a speculator or a day trader to convert into a long term investor. Even if they tell you statements like, "Yes, I am a natural born long term investor, I can feel it from the blood in my vein.." and "of course I am a long term investor, if not, how to win money?" and such, go one step further and ask them, "How long is the average holding period of your investment?" From my past experience, their answers range from: 1 week, 1 month, 3 months, and longest 6 months. Well, if you ask me, 6 months cannot be considered as a long term investment anyway. Remember Mr Warren Buffett used to say something like, "the most ideal holding period for a stock is.. Forever" (this is not a direct quote)

But, have you heard of people still holding counters they've bought more than 10 years ago and are worth less than 10% of its cost now? Do you think these counters will go back to how much it costs 10 years ago? The holders do think so, don't they? or else, why are they still holding them?
Likewise, have you heard of statements like "it's already so low, how much lower can it goes?" of course, the worst is still zero, but isn't it better to sell something worth 10 cents for 50 cents?
Another case, "If I sell now, I am making a loss. Anyway, I am a long term investor, I will wait, I believe it will go up later.." So this is a case where short term trader become long term investor. Will the wait be worthwhile after all?
There are times when things do change for the better. So, when should we decide to cut the losses? when should we wait? How about: should we start accumulating on weaknesses, as these sell down might be an oppotunity? just like the old saying "the dawn is usually the darkest". so, how? That would be another topic later.

So, is longer better (I am referring to the holding period of shares)? My answer is: it depends.
If it is a good company, which has high quality management, good earnings and cash flow, strong growth, competitive advantage over the others and etc., hold it forever, like suggested by Mr Buffett.
But if it is a bad company, hold it for one week is still considered too long.