No, my position is slightly more nuanced.
What Microsoft have built is good, provided it is very carefully marketed and positioned and what it can and can't do spelled out clearly at multiple points so that nobody is given false hope, intentionally or not. I'd go so far as to say that the word "prevention" probably shouldn't be used here. Maybe "data leak/loss resistance." Think "fire proof" versus "fire resistant".
This will mean lost sales as people who might have been bamboozled don't buy. It will also mean some others will buy anyways, and combine solutions.
None of that takes away from the solid technical work done. The problem to hand is a hard problem to solve. And, quite frankly, I honestly believe that Microsoft have done the hardest part of this in the creation of their existing technologies.
What remains is more political than technological. Zero-knowledge encryption of Azure + Office 365 can be implemented without too much fuss. They choose not to, nor to even discuss why. And if their government did turn around and tell them "you can't do that", then yes, I would say they should serious consider packing up and leaving.
I don't have a problem with the technology Microsoft is offering. I think it is good technology. But I absolutely have a problem with how it is generally marketed, how the PRs present it to journos, and how every bit of training information focuses on "look at all these features, wow!" but spend little (if any) time being clear about what it can't and won't do.
The issue here is highly political. The tech is a good start, but it is resistance-class, not prevention class. Overselling is likely to do way more harm than good.
And ultimately, it is half assed. The endgame solution required involves making some tough choices to stick up for the customer in the face of massive political pressure to do otherwise. Microsoft is out there putting hundreds of millions into trying to convince us that they're "the good guy", and that technologies like DLP "demonstrate their commitment to privacy and security".
If people start to believe that tripe - and judging by the commenters in this forum, more than a few do - then that is dangerous. And that's where the half-assedness of this whole thing absolutely becomes a real concern.
The code can be respect-worthy while the corporate positioning of the product - and for that matter, the company's overall stance across a line of products - is dangerous. And thus we have a very typical Microsoft situation in which the technology is praiseworthy but the solution (notably, how it is ultimately presented in virtually all official content on the subject) is half-assed.
I don't see any of the above as "steam rising". If anything, it fills me with a sens of...I don't know...defeat. Tired acceptance. Depression. A loss of faith in humanity, even. The sort of feeling of abject impotence and helplessness one feels when they learn that another umpteen billion dollars was squandered by politicians.
I don't have the zeal to be passionate about anything any more, sir. I have the outrage fatigue, and it's largely why I confine my thoughts on the matter to forums nobody cares about and nobody reads.
Donning the armour, saddling Rocinante and making another pass at the damned windmill just isn't in me anymore. I report what I see. I vent my thoughts into the feckless void of El Reg's forums where noone of consequence will see. That's all there is.
Crusades and causes are a game for the young.