Because
a) the common thought is that NX is the name for both the Handheld and the home console;
b) 3DS lineup for this year is full of games FOR THE FULL YEAR, while the Wii U lacks anything in the 2nd half of the year besides Zelda;
c)Mobile is stronger than in 2011, a new Nintendo Handheld could start struggling in the market unless they make something compatible with smartphones/ A smartphone;
d) most people here discriminate handhelds thinking they are not consoles imho :v