An issue that causes ongoing discussion is what is the purpose of a Planet installation such as Planet Debian . The discussion usually seems to take the less effective form of what is “appropriate” content for the Planet or what is considered to be “abuse” of the Planet. Of course it’s impossible to get anything other than a rough idea of what is appropriate is the purpose is not defined, and abuse can only be measured on the most basic technical criteria.
My personal use of Planet Debian and Planet Linux Australia  is to learn technical things related to Linux (how to use new programs, tricks and techniques, etc), to learn news related to Linux, and to read personal news about friends and colleagues. I think that most people have some desire to read posts of a similar nature (I have received a complaint that my blog has too many technical posts and not enough personal posts), but some people want to have a Planet with only technical articles.
In a quick search of some planets the nearest I found to a stated purpose of a Planet installation was from the Wiki to document Planet Ubuntu  which says ‘Subscribed feeds ought to be at least occasionally relevant to Ubuntu, although the only hard and fast rule is “don’t annoy people”‘. Planet Perl  has an interesting approach, they claim to filter on Perl related keywords, I initially interpreted this to mean that if you are on their list of blogs and you write a post which seems to refer to Perl then it will appear – but a quick browse of the Planet shows some posts which don’t appear to match any Perl keywords. Gentoo has implemented a reasonable system, they have a Universe  configuration which has all blog posts by all Gentoo bloggers as well as a Planet installation which only has Gentoo related posts.
It seems to me that the a reasonable purpose for Planet Debian would be to have blog feeds which are occasionally specific to Debian and often relevant to Debian. Personal blog posts would be encouraged (but not required). Posts which are incomprehensible or have nothing to say (EG posts which link to another post for the sole purpose of agreeing or disagreeing) would be strongly discouraged and it would be encouraged to make links-posts rare.
Having two installations of the Planet software, one for posts which are specific to Debian (or maybe to Debian or Linux) and one for all posts by people who are involved with Debian would be the best option. Then people who only want to read the technical posts can do so, but other people can read the full list. Most blog servers support feeds based on tag or category (my blog already provides a feed of Debian-specific posts). If we were going to have a separate Planet installation for only technical posts then I expect that many bloggers would have to create a new tag for such posts (for example my posts related to Debian are in the categories Benchmark, Linux, MTA, Security, Unix-tips, and Xen) and the tag Debian is applied to only a small portion of such posts. But it would be easy to create a new tag for technical posts.
Ubuntu is also the only organisation I’ve found to specify conditions upon which blogs might be removed from the feed, they say: We reserve the right to remove any feed that is inaccessible, flooding the page, or otherwise interfering with the operation of the Planet. We also have the right to move clearly offensive content or content that could trigger legal action.
That is reasonable, although it would be good to have a definition for “flooding the page” (I suggest “having an average of more than two posts per day appear over the period of a week or having posts reappear due to changing timestamps”). Also the “could trigger legal action” part is a minor concern – product reviews are often really useful content on a Planet…
Some time ago my blog was removed from Planet Fedora for some reason. I was disappointed that the person who made that change didn’t have the courtesy to inform me of the reason for their action and by the fact that there is no apparent way of contacting the person who runs the Planet to ask them about it. Needless to say this did not encourage me to write further posts about Fedora.
If a blog has to be removed from a feed due to technical reasons then the correct thing to do is to inform the blogger of why it’s removed and what needs to be fixed before it can be added again.
If a blog is not meeting the content criteria then I expect that in most cases the blogger could be convinced to write more content that matches the criteria and tag it appropriately. Having criteria for some aspects of blog quality and encouraging the bloggers to meet the criteria can only improve the overall quality.
Currently there is a Planet installation on debian.net being recommended which is based on Planet Debian, but with some blogs removed (with no information available publicly or on debian-private as to what the criteria are for removing the blogs in question). It seems to me that if it’s worth using Debian resources to duplicate the Planet Debian then it should be done in a way that benefits readers (EG by going to the Planet vs Universe model that Ubuntu follows), and that if blogs are going to be removed from the feed then there should be criteria for the removal so that anyone who wants their blog to be syndicated can make whatever changes might be necessary.