It's okay to hold and we all agree with that but to say that no matter what happens, you'll still hold then there's the disagreement from the others including me. There's a condition for this tip of yours that if you're holding other than bitcoin then you should be aware that many altcoins in the past that seem to be good have dropped significantly and turned to a lesser value. But if this is going to be applied to bitcoin, we truly agree that it's the future and no matter what the market situation is, it's better to hold not unless you're facing some misfortune and circumstances that you have to act on and choose the better option like selling a few of it.
I think we can do it with bitcoin without any doubt in it. There are quite a number of investors today who have managed to make huge profit because they bought and held bitcoins over the last few years. I also wouldn't say altcoin are useless as some of them are also potentially good for long term investment and profitable for investors, but obviously this has to do with analysis.