A million is nothing in the big scheme of things.
Valve had every right to ask for it. They have to build a team to go Mac native. That million would probably get 5 people for a year. Its not like there's unlimited potential on the Mac and why should Valve assume all the risk. I'm sure it would take millions more just to get the thing tested, produced and supported. Its not like they held a gun to his head or were really screwing him.
Game makers have been wanting to make games for Apple, its just that Apple doesn't have any love for the gaming market and will always choose more lucrative projects to spend their time and money on. They looked at gaming and a gaming console back when they were deciding what to do next. The gaming industry didn't make sense to them in terms of payback, thats why they built the iPhone.
How many reports have you heard, where the game companies asked to have an API updated or changed only to go into the voids never to be seen again?
You bet the have the right to ask. They also have the right to Steve Jobs foot in their Arse!!
If Valve wants to do it they do it. Valve assumes the risk because in business that's what you do. You assume the risk and hope your product sells.
If Valve is unsure of their product in the Mac world then don't make it end of story. You don't go around twisting stories and telling half truths about why HL2 won't come to Mac. Nor do you strut around with the attitude that "ne ner ne ner ne ner, if you want it for mac gimmi gimmi gimmi and I'll give it to yah"
That's childish BS no matter how you slice it. If anything I DARE Valve to port HL2 or Team Fortress to Mac if anything to prove to Apple that there is a viable community and that they should start putting higher end hardware in their general consumer products and then they'll see their profits soar with the influx of new Apple owners just dying to get their hands on the systems they've wanted and now the game they wanted.
But alas, I dont' think Valve is up to the challenge. I don't think they'll take the dare. Just tuck your tails and admit that all your compentent programmers have left and your only left with inept people who can only put patches out.
However if you feel like sticking it the man, I dare you to port any of your products to Mac! I DARE YOU!
(doubt if it'll work but it's worth a shot eh?)