the individual who gave the advice and also depends on the users who use it.
As for your question on "Why..." security is less than rock solid in WIFI routers?
I don't have the answer, but I think, there will be no such thing as solid security, because rock solid system, equal to a dead system.. and again its about the users needs in their environment.
So, there will be a rock solid system in one environment, but there are also an open system in other environment.
Then its also depends on the market itself... if the market required for rock solid system, then they will create such things... in the end, its only about business... just like any other things on earth.
For me the article doesn't applied to my environment, because I don't even use wep/wpa/wpa2 etc. in my wireless devices..
By the way, you should ask the writer for more detail concept of why he/she wrote the article...