What makes us comfortable with the "traditional open source licenses" is that people have been using them for decades and nothing bad has happened. But that's mostly because breaking an open source license is rarely litigated against, not because we have some special knowledge of what those licenses mean and how to abide by that
OK, fair enough. Pretend I said "not well understood" instead. The point is, the long-standing, well known licenses that have been around for decades are better understood that some random "I made up my own thing" license. And yes, some of that may be down to just norms and conventions, and yes, not all of these licenses have been tested in court. But I think most people would feel more comfortable using an OSI approved license, and are hesitant to foster the creation of even more licenses.
If nothing else, license proliferation is bad because of the combinatorics of understanding license compatibility issues. Every new license makes the number of permutations that much bigger, and creates more unknown situations.
A lot of open source, copyleft things already have attribution clauses. You're allowed commerical use of someone else's work already, regardless of scale. Attribution is a very benign ask.
https://en.wikipedia.org/wiki/Common_Public_Attribution_Lice...
What I'm saying, if I'm saying anything at all, is that it might have been better to pick one of these existing licenses that has some attribution requirement, rather than adding to the license proliferation problem.
But is it really?
Sure, it may make some licenses incompatible with each other, but that's basically equivalent to whining about somebody releasing their code in GPL and it can't be used in a project that uses MIT...
And your argument that the terms are "less understood" really doesn't matter. It's not like people know the Common Public Attribution License in and out either. (I'm going to argue that 99% devs don't even know the GPL well.) Poor drafting could be an issue, but I don't think this is the case here.
And on an ideological standpoint, I don't think people should be shamed into releasing their code under terms they aren't 100% comfortable with.
My personal feeling is that almost every project (I'll hedge a little because life is complicated) should prefer an OSI certified license and NOT make up their own license (even if that new license is "just" a modification of an existing license). License proliferation[1] is generally considered a Bad Thing for good reason.
[1]: https://en.wikipedia.org/wiki/License_proliferation