Bradley
Your wife is answering their questions this way because

THEY ARE NOT AT THE TOP OF YOUR PRIORITY LIST

and
your damn well right I would answer the same way because until you deserve for them to care about you, I wouldn't want them to wither because it is painfully clear that you are more important to yourself than they are and as long as you keep putting yourself on a pedastal high about them and your career high above those of a humble "cabinet maker" you will continue to disappoint them.

Buy some disneyworld passes now so when you mangage to crunch them in your busy busy schedule in the life of a busy and highly trained cardian surgeon, you can take them to Disney World and become the Disney dad you are obviously destined to be

exchange pleasentries while they ask for money for x,y and z
remember not to remember the names of their friends or when their band concert was or is
complain about how their mom stole them from you while you put off being able to see them because you were too busy to make it over this weekend

bow out then
and let someone else be dad
because they are only little once
and they need someone they can depend on

your pity party is a drag and your determination to make your wife the bad guy because you MADE her be the sole parent for this long because other things took precident

all I can say is
I have an advanced degree too
I missed somethings in my children's life out of necessity
NEVER because I didn't want to give up a day at work
papers have been turned in late because I needed to ruba washcloth on the head of my fevering boy
I have missed work because it was doughnuts with mom
I have lost a job because I refused to compromise my vacation time that we had been planning for

but
it is clear that no one
and nothing
is more important than your plan

you want someone to say it is OK to pursue this "dream"

Bradley...it is ok for you to pursue your dreams
let yourself detach and drift slowly out of those kidlets' lives
they need a dad
let someone willing to be a dad then be one for them without hindering them with the guilt you will place on them, without blaming their mother for your inability to care about them

you love them like you love a pet, it sounds

a pet that someone else takes care of and cleans up after and walks and plays with

for a parent, there is no choice
the fact that you are making there be one says mountains about you