IMO the closed source decision is a strategic one based on financial variables. 1. there has been vc money coming in for some time now. i doubt these companies would embrace an open standard if they want a return on their investment. people tend to put more value on something that costs them. not that it is really better, just psychologically it may be. 2. they think they have something special that can be commercialized. so far they have over 100 device manufacturers onboard so they must be on to something. 3. they look at zigbee and a. want to differentiate themselves from it, b. don't want to get bogged down by seemingly neverending meetings on agreement of standards. same thing is happening with 802.111n. the technology is being marketed ahead of finalization and people become disillusioned when things don't happen sooner rather than later.
they were able to sign on most manufacturers early on so i don't think they felt the pressure to have an open spec to sell more devices.
just another rant, i have yet to find a decent physical light switch in the US. i think the rocker style on leviton is annoying. i wake up at night to use the b-room and find myself automatically hitting the top of the switch in the dark to turn it on. i wind up having to hit the switch twice to turn it on. the cooper wiring is annoying too. it is a top/bottom rocker but on the right side. in other words you have to hit the top right or bottom right corner of the switch to toggle it. also, it is a toggle switch, meaning 1 click on, next click off. so you could hit the bottom to turn on and top to turn off, bottom to turn on, bottom to turn off, etc. this could be cool for different programming options but there is no decent labelling system physically on the device to note how you programmed it so anyone who is not familiar with it will be lost. the intouch line has a somewhat european style with the finger imprint however the 15amp clicks so loud you can hear it 2 rooms away at night. finally, the homesettings and act line have a decent style however i don't like the dimmer built into the switch. i prefer the side toggle like leviton/cooper. the timing can be hard to get used to in order to dim/brighten from the switch itself. of course you can program these setttings but i still prefer the side toggle.