I am going to dispute that statement, thus it is not "indisputable"
The lack of expenses associated with buy-and-hold investing is only an advantage over trading if it produces superior results.
Suppose investor "A" generates a long-term average annual return of 15% (i.e. greater than the general market return due to superior stock selection). This return is achieved
after expenses, which are minimal.
Meanwhile, suppose trader "B" can generate a long-term average annual return of 25% before expenses, but expenses account for 5%, leaving him with a 20% return. He would still be doing better than "A" even after expenses are taken into account.
Now, it is clear from your many posts, Mr Realist, that you are tacitly assuming that the trader cannot outperform the investor - if you are correct, then clearly the trader is irrational if he continues to trade rather than invest. Traders, however, clearly believe they can outperform the buy-and-hold investor.
The real question, then, is whether traders can outperform investors over the long term. The "advantages" of investing that you continue to mention (low expenses, low tax, less time commitment, etc.) are really irrelevent without knowing the degree to which one group can outperform the other.
Furthermore, even if we can make a general statement about whether trading or investing gives a better result, it wouldn't necessarily translate to any individual's case. Maybe, in the aggregate, investors
do outperform traders over the long term. (I'm willing to accept that that may be true.) But that doesn't mean that
every investor outperforms
every trader. (For example, it may be true that Americans, in general, are more overweight than Asians. But that doesn't mean that every American is heavier than every Asian. And you certainly couldn't conclude that every American should therefore be on a diet, while no Asian needs to watch their weight.) So even if investing outperforms trading in general (which is debatable), a
talented trader would still be rational to stick to trading if he is sufficiently good at it. It really comes down to each individual finding out what works best for them, given their skills and experience and personality.
I know of traders who have made over 50% per annum consistently over the last four years (some nearer 100%),
after expenses. You'd certainly be hard-pressed trying to convince them that they shouldn't be trading, because of the high expenses involved!
Cheers, Staybaker.