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That is because the majority of households use the pc for email, websurfing and entertainment.
It is not wishfull/geek futurism. It is already starting to happen.
In Africa they are trying to do it his way.
Most people dont have pc's but televsion so in an attempt to bring them in to the online world to access to email, education material, cloudservice and when band with gets a bit cheaper entertainment also the are starting to sell them keyboards with build in sim's and connectors to normal television.
See one of the service providers below...
About your geek/futurist statement...12 year ago we only used our phones for calls.
Maybe your statement then would have been. "I use my console and media players for games and entertainment. Also office suites on cellphones? Get the f&@# out of here. Who would use there cellphones in that way?"