Foursquare unceremoniously dropped its "check in" feature this week.

Now, the service has been re-created as a third-rate Yelp instead of a first-rate Foursquare. Check-ins are now done via Swarm, a new app launched recently by Foursquare.

The trouble with this is that, for many of Foursquare's most loyal and passionate users, checking in to locations is what Foursquare has always been about.

This kind of late-stage pivoting is something of an unhappy trend. I believe the cause of these strategic errors by companies is a combination of taking longtime and passionate users for granted while simultaneously coveting thy neighbor's business model.

That's a risky strategy. A company that goes that route could fail to succeed with the new model and also fail to hang on to its most passionate users. Then it could be acquired by Yahoo, never to be heard from again.

Twitter trouble

The poster child for this kind of error is Twitter.

People who love Twitter fell in love with it when it was a hyper-minimalist, quirky, secret-code-controlled text-centric microblog. It was minimalism that made Twitter great.

But Twitter got a bad case of Google and Facebook envy. The company redesigned its spare minimalism to look almost exactly like cluttered Facebook. The CEO of a company called Berg illustrated this perfectly by putting his Twitter and Facebook profiles side by side. The redesign is part of a larger direction for Twitter streams to move from text-based to picture-based. Twitter is joining Google+ and Facebook in the arms race that has broken out as people use images, rather than words, to compete for attention.

Twitter also embraced the card interface, which Google has rolled out to multiple properties, from Google+ to Android Wear.

Twitter has recently been testing a feature called "retweet with comment," which gathers up the original tweet in a card and essentially attaches it to the retweet. This moves Twitter away from its core idea, which is forced brevity.

Of course, new features can fail their tests and may never be rolled out. But the nature of Twitter tests suggests that the company is making the dual mistakes of taking its core user base for granted and simultaneously flirting with the business models of competitors.

For example, Twitter tested a feature that causes a link to a movie trailer to automatically appear when a user types in a hashtag for that movie.

Twitter is even considering dropping both the @ symbol, for identifying and linking to specific user accounts, and the hashtag, for linking to specific kinds of content, according to some testing it has done.

Over time, Twitter is evolving from something that people loved to something that is just like other services and has has few differentiating features.

Good news from Google?

Maybe Google will get it right.

When Google+ launched more than three years ago, it immediately identified itself as the "you're in control" social network. At the time, Facebook had serious limitations on the length of posts, whereas Google posts could be novel-length. You couldn't edit Facebook posts, or make them available via their own URL, but you could edit easily on Google+. You could put text in bold or italic and do other simple formatting. Facebook has copied many of Google+'s best features, but the initial differentiating vibe of Google+ was that of user control and freedom.

Over time, Google became more controlling. The first big removal of freedom was the real names policy, where Google claimed that it would require people to use their actual, legal names in profiles instead of made-up names.

Over time, algorithms emerged to control what you might see in your circle streams. While a new redesign enabled you to choose from between one and multiple columns of stream content, and individual circle streams could be set to "More," "Standard" and "Fewer" as a way for you to assert vague control over the number of posts you see and thus filter out some of the noise, it didn't offer the maximum user-control option of "All." For example, I have a circle of just my wife and two sons. Why wouldn't I want to see "All" of their posts?

Google also uses algorithms to flag what are supposed to be objectionable (spammy or irrelevant) comments. In recent months, this algorithmic filtering of comments has gotten both more aggressive and less accurate.

But there are signs that Google may be intending to return Google+ to its roots as the "you're in control" social network. The first is that the company recently canceled its real names policy: "There are no more restrictions on what name you can use," it announced.

Also, in a recent post about the algorithmic control of comment flagging, I asked a Google+ team member whether there was any way to turn it off, and he replied that it's something they're talking about internally at Google. I don't know if they're discussing the addition of an "All" option to allow users to see all of the posts in a stream, with no noise-filtering.

Overall, it seems to me that Google may be getting back to its roots as the social network where users are in control. If it's not, it should be.

I believe that instead of abandoning passionate users and trying to copy competitors, social sites and apps need to look deep within themselves and understand what made their passionate users so passionate in the first place. Then do more of that. Not less.

This article, "If You Can't Check In, Is It Really Foursquare?," was originally published on Computerworld.com.

Mike Elgan writes about technology and tech culture. You can contact Mike and learn more about him at http://Google.me/+MikeElgan. You can also see more articles by Mike Elgan on Computerworld.com.