He's already a solid Top 4 and the talent to become a solid no1 defenceman... what's the problem of him being chosen no 1 ?
How many defenseman would you rate ahead of him drafted between 2005-today that have gone later than 1st overall? I'm not going to sit here and make a list but there is quite a few. His development hasn't been as a upward and quick as many people thought it would be, but your right he's still a solid defenseman and has another 3-4 years to round his game before he's in his prime anyways.
What hurts popular opinion on E.Johnson is that he was drafted ahead of Backstrom and Toews, both have become elite two-way #1 centers and one of them has a cup.