Rabotai,
I (and I doubt most if not all) of the commentors on this thread are not qualified to judge on the permissibility of the Kosher Switch, as we lack both smicha in Shabat and shimush. Nor we can really know who said what, which Rav said what, since the whole issue is shwred into confusion, finger pointing and strife as it is unfortunately a pattern in discussions where there are interests and halacha.
However, even though we may not assume the KS is lechatehila, I believe it is desirable for a number of reasons:
1 – Most probably it would not be a problem if lighten up by a goy. If the lamp is fluorescent with no iron bulb inside, then it is even less of a problem, because hachraat haposkim is that such a lamp is Derabanan (we are talking, at the worst, about a shvut deshvut in a grama). You don’t have to hint or anything. You may directly ask to a Shabbos goy how exactly you want your lights in Shabat. There is no concern of zilzul, because obviously YOU don’t turn anything on-off. Remember that in Israel generally people don’t think about Shabat observance with amira lenochri in head, since it if often difficult to find a goy. Maybe this is relevant to not allowing it there, but how about in hutz laaretz?
In our Jewish community of Brazil, it is not uncommon to have housemaids in Shabat. With KS the issue of asking her to lighting lamps is over: no hinting and time-wasting, lechatehila.
2- Elderly people, kids, etc etc. as someone pointed above.
3- If you mistakenly switch the light on/off, you don’t do any hilul Shabat beshogeg;
4- For people starting their observance through Kiruv, especially if their families object leaving the lights on the whole day;
5- Not-so observant (traditional) people who don’t mind turning lights on/off albeit they know it’s no good, but from the other side if told that they could keep more of Shabat just installing a switch, would prefer to do so.
Again, I’m not defending it lechatehila for everyone as I’m not a posek. But shouldn’t we welcome the invention as it can prevent sins and make Shabat observance better, for a wide range of people?
Thank you and Shabat Shalom!