Holding is one of a good strategy in cryptoworld especially in this bearish situation but its depend on what kind of project coin you will hold for long term choose a good project that have a great technology and developer like ethereum, neo and eos.
Dont ever hold an altcoin that have no goal in their project.
True, holding will only be worth it if the coin/coins you are holding have values. Even if it looks very hard right now, I still believe in holding because there is no choice if most cryptos are on dump. Just like what @dark08 stated, holding still depends on the coin and for how long. Bitcoin and ethereum are best for long term while altcoins are good for short term and day trading.
I believe that most bitcoin earners will choose holding right now because it is the most preferable and smartest thing to do when the market price is low. We know that it is the best thing to do rather than selling.