Management often assumes that they did their job when they handed in specs.
    And I often assume that there is nothing else for them to do.

I can't say for certain that you're a bad developer, but if your management thinks throwing specs over the wall is "doing their job" they ARE bad at theirs. I'd argue that you fail your part of the job in that case if you DON'T have any questions.

As for the slipping estimates, are you part of the process that generates them? If not, it's back into "your managers are bad at their jobs" territory.