Nope. This is tottally non-sense. Sure Sony has (had) some great franchises, but saying that they´re better than Nintendo franchises is, at most, only personal preference. The videogame market doesn´t agree with that. Just take a look of the 20 best seller games of all time (here in VGChartz)... 19 games are from Nintendo and NONE are from Sony.
If Nintendo´s games sell better it´s sure to say that they have their qualities and merits of engaging more gamers than Sony´s productions. And that has nothing to do with adult/mature content....
And this talk of "Nintendo only makes games for kids" is kind of old and dumb. Nintendo games are appreciated by gamers of every age and taste. Nintendo games are like Disney movies: they´re something to appreciate and enjoy, not aimed to pre-teens pretending to be teens or teens pretend to be adults.