Sad part is its not just "People" Google's AdWords and Microsoft's AdCenter are both SOAP. Par for the course from Microsoft, but I'd expect better from Google.
The super annoying thing is worrying about WSDL, XML namespaces and xpath for something as simple as getting a count of alerts.
In JS, you have no client library so you're required to roll everything from scratch.
PHP has oauth, more demo code and better docs, I've recently been using it to build a JS lib for a work project.
The thing is, rather than maintain one client library, half maintain two others, and have a bunch of unofficial libraries, if they just made and documented a REST interface everyones lives would be easier.
Big problem is at the moment that PHP has Oauth for pretty much everything except report downloading, which is essentially separate from the rest of the API.
Hoping they fix this before I launch, as most of the good of OAuth is negated if I still have to collect a username and password for report downloading.