In Northern Europe you have to keep a minimum temperature or things like your pipes might burst when its -20C outside.

Pets. Other family members. Plus the fact that you're "daytime" heating/cooling a home from 6:30-8:30 am and 3:30-10 pm anyway, and that modern or updated homes keep their temperature for several hours. So the debate is really over a few degrees for a couple of extra hours (Vs. heating an entire other building that may not otherwise exist).

I know at our workplace heating on Monday mornings has to start several hours earlier than on Tuesday because the office lost almost all of its built-up heat from the previous Friday. I also know that they continue to run the heating on holiday-Fridays/Mondays because if they don't by the following Monday/Tuesday, the temperature will drop too low and could damage equipment.

Well, you may live with other people who are in it when you're not, causing it to be heated anyway.

But I guess the answer would be that people can't abide the thought of one uncomfortable minute in their own home, and don't bother figuring out how to program the thermostat.

Typical American house uses a heat pump (basically an AC run "backwards") with a single thermostat (bigger houses might have multiple complete systems).

If you turned the heat off at 7am as you left for work, the house would probably be below 60 when you got home, and take most of the evening to reheat, only to be turned back down again at bed time. I don't know anybody who manually does any of this - at best, they have a smart thermostat that lets them schedule home/away time or uses cell phones as presence sensors. And even then, they'll lower the heat 5-8 degrees, not turn it off completely.

In northern states people have to leave their heat on during the day to avoid plumbing issues or to keep pets comfortable.

because it’s more expensive to let it get cold and then heat it back up again