Trading is good actually if you want to grow your holdings. I mean holding .5 or 1 btc for me is not fruitful. Unless you hold a bunch of bitcoins, holding is the answer. And not many holders have thousands or even hundreds of bitcoin.
You are right on this, holding much of stash in Bitcoin will be more profitable than just holding some petty stash in Bitcoin. Although 1Bitcoin = 1Bitcoin but without a good stash of this coin your holding is mere like a waste compare to when you're able to trade some few stash to make few stash addition to the holding. Sometimes, those without the knowledge of trade shouldn't get into it becasue it can ruin their holdings, despite their minimal stash hold your coins and don't get into trade to incur loss.