The reasons may vary, but I think more about art in assessing investment in Bitcoin. Why I say that is because investment talks about expecting profits and it takes art to achieve it all. But most people talk about strategy because with strategy we will make investments more profitable. Bitcoin became hedged in an attempt to achieve financial freedom and it was hardly found in previous investments that existed. About a strategy or purchasing pattern that is carried out and maybe that is the basis for how someone should learn.
But staring at the computer to see Bitcoin's journey in the market is a satisfaction in itself for investors. If we talk about calm trading, then your assumption that you don't need to look at a computer will invalidate all these arguments because they have to use a computer to carry out trading. So this small reason is not a reference because everyone has a different view of the involvement of investing in bitcoin.
Honestly, I did not quite understand what you meant by art. And why, in your opinion, this art approach contradicts strategy in trading? I would say that developing strategy only benefits your way of trading, because you define some standpoints for yourself which help you navigate through the market. And following strategy doesn't obligatory mean that you would have to stare at the screen all the time. It really depends on your trading style and your self control abilities.