How you use your EV helps determine how useful heat pump would be. I frequently drive 455 miles (732 km) to my hometown, with a longest non-SC stretch of 174 miles (280 km). If I borrow a friend's S85 (15% degradation), I can drive 65mph+ (105kmh) the whole way in summer; but at 14F/-10C with snow, it requires a 1-hour L2 charge on that long stretch. If I could reduce heating energy by 3kw, then I could make that drive without stopping. So for that particular drive, in winter, having heat pump would be as useful to me as the range difference between SR and SR+.
Of course, just buying a bigger battery would compensate for no heat pump; plus, you'd also get to drive further in summer (bonus!). But I think there is a potential customer satisfaction problem with having a car which requires an extra 1-hour stop only in winter. When someone invites you over, it's a bit weird to tell them that you'll come only in summer. Seasoned EV drivers will use a trip planner, and will think about headwinds, road surface and temperature. But until everyone drives an EV and thinks of these things, having such a different range summer vs. winter will make it harder to convince ICE drivers to switch to an EV (at least, where I live).