I think you are missing the point -- The Roomba barely works better than YOU cleaning floors. And this weeding robot does a crappy job compared to ME weeding my garden.
But our Roomba was a miracle worker when my wife was laid up in bed for 6 months with a shattered pelvis and I was also extremely sick. And while I know how, and have time, to weed my garden, this robot could help people who don't have the time or energy to keep up with such thing. And the stories don't even have to be that dramatic - in a family with 5 kids, there are better ways to spend time than vacuuming carpets.
Sometimes having devices like this isn't about the quality of the work - it is just about the work getting done at all, so your time can be spent on more important things.
But our Roomba was a miracle worker when my wife was laid up in bed for 6 months with a shattered pelvis and I was also extremely sick. And while I know how, and have time, to weed my garden, this robot could help people who don't have the time or energy to keep up with such thing. And the stories don't even have to be that dramatic - in a family with 5 kids, there are better ways to spend time than vacuuming carpets.
Sometimes having devices like this isn't about the quality of the work - it is just about the work getting done at all, so your time can be spent on more important things.