Re: Bewildered. (That's grown-up speak for "wtf")
To misquote Edmond Hillary, They are connected to the internet because it (the internet) is there.
They can, um, ping your iphone when the dishes are done. Let you check that the kids have run the dishwasher from work. Keep statistics about powder usage. Disable the machine if it is found to be used by terrorists. The possibilities are only limited by your imagination...
The next dishwasher that I buy will certainly be connected to the Internet of Things ... because I won't have any choice.