The better question would be why would lightbulbs need wireless connectivity.
I now see two distinct kinds of lighting: task and ambient. For task lighting, I still want fast manual control, for which dumb bulbs are fine. But for ambient lighting, I want it to be almost entirely automatic.
In the morning, my lights gradually come on, starting very dim and warm. In the middle of the day, they're bright and like daylight in color. In the evening, they slowly dim and shift toward red. They go out on their own about when I want to go to bed.
One good part is that I don't have to mess with lightswitches all the time. But the much more valuable part is that it helps me establish a strong diurnal body clock. I now wake up on time without an alarm, I get enough sleep, and my mood is more even.
One alternative would be to put the smarts in the switches, as early home automation had it. But my old wiring isn't compatible with that. And even if it were, that at best gets you brightness control, not color temperature control.
If anybody's curious, my code is here: https://github.com/wpietri/sunrise
For what it's worth, I avoided tying the lights to actual daylight hours. In winter I tend to get a bit gloomy, and so part of my goal was to make my brain think that it was never really winter. It seemed to help this winter, although it's hard to say for sure.
How are you liking your setup?