For many people, including me, the value proposition of Nest isn't worth the cost. There needs to be a modular middle ground between Apple level in-home automation software and unassembled kits. I don't see myself spending over $100 for a thermostat. Ever.
With a combination of hard-to-modify interior walls and an open plan design where wall-mounting often doesn't make sense, going with wireless thermostats was an easy choice.
Now the thermostat in the main living area can be moved depending on whether we are using the wood stove, and the kitchen thermostat that was always too far from the radiators and too close to the oven can be placed where it actually keeps us comfortable.
Unless your house is new-ish and thermostat placement was carefully considered, the benefit of being able to easily move a thermostat and experiment with placement can be enough of a benefit to justify relatively expensive thermostats.