It actually is the source of the problem because his rules end up being inconsistent.
Generally, rules about what constitutes "good taste" or "aesthetically pleasing" are derived not just from wealthy people but from established wealthy people. This is something that goes back centuries, to when Western cultures first started having a bit more mobility and it was possible for a person who wasn't born into a family of hereditary land-owning aristocrats to accumulate enough wealth to start having nice clothes, a large house with servants, etc.
The hereditary aristocrats, of course, didn't care much for this and so wanted some way to distinguish themselves from the jumped-up nouveaux riches, some of whom even became rich enough to buy (or obtain through rendering financial "service" to a monarch) their own heritable noble titles. And so began a complex, inconsistent and ever-changing set of standards of aesthetics and behavior, designed to act as a kind of shibboleth: if you hadn't been brought up among people who'd been doing this their whole lives (and who in turn were brought up by people who'd been doing it their whole lives), you'd never quite get it right and the older established noble families would be able to tell you didn't really belong to their social class (and would treat you accordingly).
Many of these rules about architecture are artifacts of this system: they are the evolved result of established wealthy families trying to find ways to make sure their homes were distinguishable from the homes of the vulgar arrivistes.
And in fact this is precisely what the backlash against the "McMansion" is about. Newly upper-middle-class people, and even newly-extremely-wealthy people, can still be singled out by the way their homes merely imitate the homes of established old-money people, and by picking out the ways the imitation fails. And remember that to the old money, a Silicon Valley billionaire who started out in a working-class family is worse -- because they jumped far too many social classes in one generation -- than someone who merely hopped into upper-middle-class suburbia. So just looking at recently-built megahouses won't tell you much because many of them will be built to the tastes of people who, by definition, cannot have good taste (remember: if you haven't had it for at least three generations, you don't have it at all).
Generally, rules about what constitutes "good taste" or "aesthetically pleasing" are derived not just from wealthy people but from established wealthy people. This is something that goes back centuries, to when Western cultures first started having a bit more mobility and it was possible for a person who wasn't born into a family of hereditary land-owning aristocrats to accumulate enough wealth to start having nice clothes, a large house with servants, etc.
The hereditary aristocrats, of course, didn't care much for this and so wanted some way to distinguish themselves from the jumped-up nouveaux riches, some of whom even became rich enough to buy (or obtain through rendering financial "service" to a monarch) their own heritable noble titles. And so began a complex, inconsistent and ever-changing set of standards of aesthetics and behavior, designed to act as a kind of shibboleth: if you hadn't been brought up among people who'd been doing this their whole lives (and who in turn were brought up by people who'd been doing it their whole lives), you'd never quite get it right and the older established noble families would be able to tell you didn't really belong to their social class (and would treat you accordingly).
Many of these rules about architecture are artifacts of this system: they are the evolved result of established wealthy families trying to find ways to make sure their homes were distinguishable from the homes of the vulgar arrivistes.
And in fact this is precisely what the backlash against the "McMansion" is about. Newly upper-middle-class people, and even newly-extremely-wealthy people, can still be singled out by the way their homes merely imitate the homes of established old-money people, and by picking out the ways the imitation fails. And remember that to the old money, a Silicon Valley billionaire who started out in a working-class family is worse -- because they jumped far too many social classes in one generation -- than someone who merely hopped into upper-middle-class suburbia. So just looking at recently-built megahouses won't tell you much because many of them will be built to the tastes of people who, by definition, cannot have good taste (remember: if you haven't had it for at least three generations, you don't have it at all).