Stack Exchange sites sometimes get closed if they don't show "enough" activity during the beta stage.
What's the intent? I mean even with low activity they are working and they don't harm anyone.
What's the good in closing a Stack Exchange site with low activity?
I mean even with low activity they are working and they don't harm anyone
This is a misconception. A site with low activity runs a very high risk of losing what small expert membership it may have (from boredom, burden, etc.), which in turn limits the site's utility to the internet at large.
One of the beauties of the Stack Exchange network is that people can ask questions and get fairly reliable answers in a respectable timeframe. Someone visiting a low activity site expecting the same level of response is very likely to find themselves disappointed, which weakens the reputation of the overall network.
A site that fails to attract enough membership to have a reasonable and sustainable level of activity is kind of like abandoned property. Left to sit unattended, it will become an eyesore, with less and less people to pull the weeds and water the grass. However, in tearing it down those concerns are removed, and the users are set free to find a more suitable area of the internet to call home.
That's not to say that closure is an expected potential outcome, of course. The goal is always for sites that get launched into beta to succeed, and closure is a last resort for when it becomes clear that simply isn't going to be the case. Low activity by itself doesn't make that indication though, so long as there are signs of growth.
The sites that do eventually get shut down are those that have very little sign of growth on top of levels of activity that barely register. For whichever of the many reasons discussed elsewhere, this trend indicates that these sites are just not workable within the Stack Exchange network at this time. As there's little incentive to maintain something that isn't working, getting rid of those sites and devoting the resources and energy to supporting the ones that are doing well seems like the wise thing to do.
What's the good in closing a StackExchange site with low activity?
Not having to maintain a site that doesn't have a chance of ever becoming profitable. Stack Exchange sites may be community driven, Stack Exchange Inc however is a for profit company.
Other than that, a low activity site usually means that moderators and a handful of high rep users are doing all the moderation, and trust me that gets old soon. Community moderation is at the core of any Stack Exchange site, and if the burden falls only on a few people, the site will soon turn into a crapfest when they get bored or too tired to care anymore.
I don't care if my SE beta is profitable or not. I don't either, however cool features and everything else the team is doing for us don't come out of thin air. And "profit" doesn't always translate to money, I had more the team's energy and time in mind when I was writing the answer.
SE is a for-profit company - as referring to the financial (or at least, pragmatically beneficial) side of things. Didn't realize about SE employees at the very beginning of the beta - although that would be pretty similar in successful vs. unsuccessful betas, no?
Why not? SE have so many sites and they are also increasing, if one of the site does not have any progress at all then why not delete it.
SE have proper scheme to check the progress , so there is no chance of wrong closing of site. Read this post for details about which site can sustain here and which have chance to got closed.
More sites doesn't means more growth , so there is no reason to take the burden of unsuccessful site on the shoulder of SE.
Being in beta on Stack Exchange is different than a software being in beta.
Software in the beta phase will generally have many more bugs in it than completed software. In the case of a beta SE site, these bugs aren't specific to the code the site is being run on, but are specific to the concepts and ideas of the site.
The focus of beta testing in both cases is reducing negative impact on the users.
The users of a beta version of software are called beta testers. The same concept applies to Stack Exchange beta sites. It may not seem like you're testing a site - It's fully usable just like a site that's out of beta - but you are.
When a site is deleted, it's because the beta test failed. That doesn't usually happen with software, but here a beta is an experiment.
Getting a site created using Area51 isn't the end of the site creation process. It's the beginning. That means that the sites that were deleted were tested for viability of concept and you found that the concept wasn't a good fit for the network (at this time).
Beta version software is often useful for demonstrations and previews within an organization and to prospective customers. Think of beta sites as a preview of what can be, or in the case of deleted sites, what could have been.
