One of the most common VIP setups I have seen over my time is a 722 and a 211, or a 722 and a 612. A lot of houses have three televisions, with the upper norm being a 722/222 combo, or a 722/722 combo. Of course, I have seen many, many more receivers on an account, but I am guessing that the idea for the Hopper was to have 3 tuners, as most houses have a maximum of 3 or 4 tuners, and 4 tuners are rarely used at the same time. Realize, what I see or have seen is anecdotal, there are 14 million customers, and I have probably seen 20,000-30,000 accounts in my time. A small sample, really. Thought process was that 1H/2J and 1H/3J would cover most customers and their needs.
Then, of course, came the expansion where customers could get 2 Hoppers. And for some, 3 Hoppers (as long as they buy Hopper #3).
I remember when the Hopper rolled out. Great system, but I remember even then thinking that 3 tuners wasn't enough for a portion of the customer base, and wondering if we'd ever add more tuners to the Hopper. We didn't do that, of course. What we did do was make Hopper #2 far more affordable (up-front costs) over the last 15 months or so.