Thanks for reporting this! The issue is that, as some other dApps, we are using steemconnect-js, which saves us a lot of time developing. Steemconnect-js provides one function for login/vote/comment/... and depending on if and which browser extensions you have installed, steemconnect-js automatically chooses, Keychain or the Steemconnect browser extension. The problem is, that if you have both extensions installed, steemconnect-js forces the use of Steemconnect instead of Keychain, assuming that users who have both extensions installed prefer Steemconnect.
So, basically, we have three options to change this:

1.) We remove the Keychain login button for users who have the Steemconnect extension installed. This is the easiest solution and wouldn't change the current behaviour, but avoids confusion. Steemconnect offers the same functionality as Keychchain, so functionality would not be affected.
2.) We fork Steem Keychain and force using Steem Keychain over Steemconnect if both are installed. This would not involve much work, but mean reoccurring work to keep up with updates of steemconnect-js.
3.) We manually implement Keychcain functions instead of using steemconnect-js and trigger either Keychain or Steemconnect depending on which button the user clicked to log in. This would be the best solution, but involve quite some work holding us back from working on new features while benefiting only a small number of users who have both extensions installed.

We are currently considering all three options, which one would you prefer?