So your questions, does PHP really need all the added complexity of this?
That doesn't matter. If you don't need it, don't use it.
Does it really help solve the problem, or did you just add a new maintenance nightmare?
This question is a false dichotomy. First, it wasn't trying to solve any other problem then getting traits to work. So yeah, it solved that problem. Second, new code always adds new maintenance concerns. Whether or not it's a nightmare depends on the quality of code, which seems to be above par in this case.
As Nycto pointed out in this thread, there is a "Traits" patch which seems preferable to this code. It's likely that OP didn't realize it existed and did reinvent the wheel. But still, in terms of an exercise in PHP, I found it quite cool.
It's also worth noting that PHP will most likely be adding Traits into the core language at some point. A patch has been available since 2008:
http://wiki.php.net/rfc/traits
Hell, if you really need traits (you don't), apply the patch. Just don't mutilate your code base.
Regardless, I think this is a pretty cool idea. It seems like a lot of effort to emulate what's (arguably) a missing language feature, but for those of us who are stuck in PHP for one reason or another, it's an interesting development.
And I think you're right that YC's commenters are by and large not PHP developers. I've only known a couple of real hackers that work in PHP, and even they didn't work in it by choice. Though it makes me a little sad to say this because PHP was the first language I learned (hooray sentiment!), I hope PHP dies off soon. It has matured in recent years, but unfortunately not in any new directions. I'm gonna go out on a limb and say that the vast majority of PHP programmers are idiots who couldn't code their way out of a paper bag, and the better PHP hackers tend to be enterprise-y, as that's the direction PHP is headed nowadays.
I consider myself a pretty good PHP programmer, but you're right, most of them out there don't deserve the title "programmer". I'm so disgusted by 99% of the open source PHP crap out there.
That said, I do look forward to learning new languages and new ways to develop on the web (what I really love doing).
In response to the first bit, a friend observed that Warnock applies.