It's worth noting that I think both should exist.
No software dependence at all if possible, just a basic microcontroller and firmware.
Agreed, I just want a ZigBee endpoint as well.
As for the smart home stuff, I already have it in place, so it's no additional expense.
Control wise, your method would be fine for someone techie and motivated. It would annoy the hell out of some non techies, particularly if they had vision issues (think OAP). It would also close down the option of relatives helping out by monitoring it remotely.
As I said, different target audiences. Both have their places. I just wish the smart option did its job properly, rather than the half baked options we keep getting.