Some other points:
Mafia doesn't care about 1-meat undercutters. Many people buy items through Mafia.
Item farming tends to be more lucrative than meat farming but takes more effort (e.g. understanding mall trends, willingness to sit on items until they spike in price, e.g. at the start of a new pvp season) and is generally much more variable. However, given that meat farming can consistently yield 4m+ / day with practically zero maintenance effort, provided you have the right (large set of) IotMs, I personally don't find item farming worth the effort.
Honestly, though, if you want to make meat on a large scale, you're going to make investments.
Finally, as far as I'm aware, Jick's opinion is that everyone who plays KoL should be playing it to read the funny jokes (not to strive for faster ascensions, or build huge collections, or amass a hoard of wealth, or mny other reasons individuals continue to play regularly past the 2-month mark), so I tend to take his opinions on that front with a grain of salt.