Fetch came in around 2015, and XMLHttpRequest wasn't consistent in the way different verbs were handled, like redirects, as this blog post[0] from 2006 points out:
> Basic redirect support is pretty universal, but things quickly fall apart on most browsers when you do tricky things like use non-GET/POST methods on redirecting resources.
There were other things too, I'm not sure CORS supported anything but GET and POST early on either. Wanting consistency and then sticking to it isn't an inherently bad thing, there's a lot to know, and people don't update knowledge about everything (I'm speaking generally as well as including my self here).
Fetch came in around 2015, and XMLHttpRequest wasn't consistent in the way different verbs were handled, like redirects, as this blog post[0] from 2006 points out:
> Basic redirect support is pretty universal, but things quickly fall apart on most browsers when you do tricky things like use non-GET/POST methods on redirecting resources.
There were other things too, I'm not sure CORS supported anything but GET and POST early on either. Wanting consistency and then sticking to it isn't an inherently bad thing, there's a lot to know, and people don't update knowledge about everything (I'm speaking generally as well as including my self here).
[0] https://www.mnot.net/blog/2006/01/23/test_xmlhttprequest