Gia translates for us the post Kiyohiko Azuma made on the topic.

First of all, he denies a displeasure with Azumanga the animation. Not that I ever believed the rumors, since it was extremely faithful to the manga and translated the spirit well.

But as for Yotsuba, it seems that he is concerned that little details would not translate as well.

でも、「よつばと！」なら、よつばがよいしょよいしょっと階段をおりてきて、てけてけと廊下を歩き、 でんっと玄関に座ってヘタクソに靴を履き、よっこらしょっと重い玄関のドアを開けて、元気よく家を出て行く。 そういう、普通アニメでカットされそうな描写もやらないと、アニメにする意味が無いと思うんです。 で、こういう日常の演技描写はアニメの最も苦手とする分野です。

I'm not sure I agree, but he is the mangaka here, so I defer.

UPDATE: Gia scooped ANN. Way to go, girl! But next time, include the link to the original.