>"and get management to make a donation in kind"
Unlike FreeBSD and pretty much every other serious donation-supported project (including NetBSD) the OpenBSD Foundation is not a [strike]legal non-profit[/strike] "tax deductible charity" (in the US that'd commonly be a 501(c) tax empty). So donations are not tax deductible and may run into barriers that others sail through. Many of the matching programs I've seen for example simply have official non-profit status as a flat-out requirement. While of course it might be possible to negotiate exceptions with management, just in having the conversation at all we're already talking massively more friction, and friction is the enemy of spending.
OpenBSD has some little bit of handwaving about it (Canadian, too much trouble) which may well be valid in isolation but is irrelevant in the larger picture, and feels more like a common pattern of prideful disdain at being about "anything but the code". But to the extent money from non-coders is considered important, the interests of non-coders also have to be at least mildly considered if an increased response rate is desired. It's the 100% right of OpenBSD to make it a PITA and have snark and proudly run rough sites and such, but of course that's going to have natural consequences in interactions with the rest of the world.
There's no right or wrong answer here, but I don't think your "it's pretty sad and says a lot about the IT industry that they are not" actually fully captures the situation. Other foundations are registered non-profits, have somewhat nicer pages (not crazy webapp monstrosities, but even little things like simple acknowledgment of smaller donors that OpenBSD blows off), and so on. Donors are special and rare, and a bit of personal recognition and appreciation is free and can go a long way. A lot of coders may dislike the softer general human networking side of things, but tossing it aside will generally result in a reduced experience unless there is some other form of stickiness.