I think you’re exactly right about the grand old houses of the past getting cut up—that’s exactly why people have come up with these types of covenants. Restrictive covenants are a tool that property owners can use to protect property values.
What is really bizarre here is that I live in a rural area, no developments, no covenants, all single family, and most homeowners are private property rights fanatics -- object to ordinances on setbacks, height, road right of ways, emergency access, or anything else, also designed to protect property values as well as safety issues. Then these same homeowners buy a place in FL or AZ in a rubber stamp development, with not only ordinances but also covenants up the kazoo, house color, mailboxes, no parking, landscape, etc. -- can't do a darn thing -- and they say the love it. Maybe the trick is to impose ordinances governing everything, just like a set of highly restrictive covenants, and then we will have happy property owners.
On the other hand, while possibly intended to protect property values, covenants all are designed to keep out of the development "the wrong kind of people" and promote a certain "culture," and when property values drop, as currently, the covenants are a major impediment to rescuing a gargantuan, unsustainable development, and giving it a chance to morph into something which is reasonable and sustainable, it that is even possible.