My thought is that for any business-critical service, you need to have bought the service from person-to-person sales channels. Many boring meetings where they walk you through a slideshow of their service even though you already have it working. Many meetings worth of negotiating a price that's 10x the off-the-shelf price. All instead of, you know, making your product. It's just the cost of doing business -- $5/user/month if you're ok with them shutting you down because of a malfunctioning cron job, $30,000/year + meetings if you want someone's email that has to look into your problem. That's how software is these days, and unfortunately, literally everyone wants a piece. No task is too trivial to justify a 5 figure yearly cost, it seems. (Most recently, a well-known company tried to get that much out of me for hosting a static website!) There doesn't seem to be any market pressure to correct this problem, and I don't really understand why, but someone stands to make a lot of money if they crack the code. In the meantime, there's you and a problem, and giving the vendor your time and money can get the problem resolved. (Yup, you have to reward someone that's wronged you, because you already wrote code against their proprietary API. That's just how it is these days, and you have to accept it if you want to get anything done.)
I agree with the other comments that relaying phishing to internal users is probably what they dislike. There, of course, isn't a good solution beyond using some open platform. Your self-hosted IRC server isn't going to cancel your account because someone sent a phishing link, for example. But, nobody will know how to connect to it anyway. Sigh!