In my opinion it is a goal and motivation, with the intention of collecting 1 BTC there will be a sense of enthusiasm to get BTC from trading or bounty and when you succeed in achieving it there will be an extraordinary feeling.
That's for sure. It definitely gives a feeling of satisfaction when you have finally earned 1 BTC. Earning a portion already makes us feel happy. How much more if it's 1 BTC, right?
And, as you've said, it's also a goal or a challenge. Like this year, I should be able to earn this amount then next year, another amount. And for a given time, you challenge yourself earning bitcoin until you've reach your goal. 1 BTC is already big for me. Especially when the price is at its highest peak.