Because the official word is not "no". Ongoing support encourages the powers that be to continue keeping an eye on it.
Originally Posted by Alexander Turcic
Thank you for the suggestion, guys. At this moment, we do not feel comfortable installing Tapatalk support at MR, because it requires adding a plethora of 3rd-party server-side scripts, which can add a whole lot of new potential issues (bugs, security). We keep a close eye on it though, and are also evaluating alternatives, which includes improving our mobile site to make it specifically more iPhone/Android-friendly.