It's a facile statement. A significant fraction, if not the majority by far, of most companies' expenditures is in salaries which go mostly to pay rent or mortgages in most places.
Which is what “landlords” means; not the company’s landlords. It’s far from facile.
I think the point was that it's not a phenomenon exclusive to San Francisco.
askafriend's comment is correct: most companies, regardless of industry or location, spend a significant fraction of resources on salaries. The notion that "it pays landlords" isn't unique to the bay area or VC-funded companies, by far.
I could have sworn "in most places" wasn't present when I replied, but I might be misremembering.