trading bitcoin with a small amount is not profitable, you need to buy a huge amount because the price is trading so high. and if a person have little amount of money then there are so many other cheap altcoin, by trading one you cam make a good profit but you must study the market and different ICO and must select a good potential coin which is also not such an easy job. you need to have good experience in crypto market and only then you can do so.
You have a point but with the current bitcoin price rate, even for an average amoount, we can sees that our profits are decent and no doubt can considered as not a small profit. Somehow while we are on progress, we are sure that our bitcoins/money that is using in trade will increase soon, slowly but surely.
But it can't applied to altcoins as to make profit here noticeably, we need a massive amount of coins on hand so that in case of a pump, the profit really moves. Just don't forget that in case of price dump, you can also noticed your big loss.