I would've been disappointed in that response, too. I recently reminded my husband of my 2 yrs. sober - he never mentions my "anniversaries". (I know if it was him, I'd have marked it on the calendar and been giving him all sorts of praise.) When I push for a compliment he does say he never thought it would be possible for me to do it, & he's proud of me. Still, I have to bring it up. Maybe he's afraid if he heaps too much praise on me it'll jinx things.
Maybe you could ask him - the way you asked us - to explain to you why he seems hesitant to give you some "atta girls". We aren't staying sober for anyone but ourselves, hopefully - but some recognition is sure appreciated, isn't it?