OK, my two cents worth:
1) Most of the feed providers have voluntarily hosted a feed. That means that they provided the equipment at their own expense and LiveATC has provided the interface to the LiveATC network. The provider of the feed, in most cases, offers to provide a feed voluntarily so that they put a particular frequency or frequencies that they want. If they want to add more frequencies, it is generally up to the feed provider. They may choose not to for whatever reason.
2) In the past I have been asked to try out different frequencies on a number of my feeds. I have no problem entertaining those suggestions. For me it's easy. Some of the feeds I provide are sitting right next to me on my desk. But I also know that there are many feeds out there that are not so easily accessible. Some of my other feeds are at other locations and if there should be a problem with one of them, it's not always so easy to fix. I can't always just drop what I'm doing to go and take care of a problem or try a different frequency. And that problem would be the same, I'm sure, with all the other remote feeds here on LiveATC.
3) Of course, then there are those who might not be willing to experiment. And that's their choice.
4) When feeds go away, in most cases, it's because the provider for whatever reason can no longer offer it. Maybe he's moving, maybe his landlord doesn't like the antenna on the outside of the building, maybe he lost interest, who knows...sometimes feeds just go away without any notification. It happens. There's usually nothing that can be done about it. Hopefully, someone will contact LiveATC and offer to provide an enroute ZOB feed.
5) I personally prefer to listen to ENROUTE feeds. So, I'm happy for all the enroute feeds that do exist. But I also understand that they might not be there forever so I will take what I can get and enjoy those that are available.
Bottom line? Enjoy what is available. LiveATC is the best site for listening to ATC. More feeds appear almost every day, even ATIS feeds. Just like there is an audience for enroute feeds, there's also an audience, smaller as it may be, for ATIS feeds.
Ron