This simply isn't possible for any contest that uses Subs as a criteria. Are they going to monitor every social media account of every entrant? What if someone posts to their Facebook when the contest starts and deletes it before the judging? What if they use Facebook, Twitter, SnapChat, Insta, Whatsapp, Google groups, Tumblr, their Patreon, their private Discord channels? You want to militarize the entire Tapas forum user base to police what they think is acceptable for other entrants? Everyone spying on each other, taking screencaps, shaming them in public because they have the audacity to be excited for a contest?
Where does it end? Someone who has been posting on Tapas for 5 years has a better chance at getting subs quickly than someone brand new. Is that also "unfair"? Why? Nothing is stopping anyone from creating accounts on every social media platform there is. "It's not fair that so-and-so already had a following on Wattpad." So what? Anyone can make a Wattpad and spend years building their audience. If Wattpad gives everyone so much of an edge, why isn't everyone who wants to win doing it too?
The contest has popularity rewards and Judge's choice awards. You're not going to get a "quality only" award out of Tapas because there's no such thing.
Tapas definitely needs to make their rules and guidelines much more clear than they currently are. Definite content restrictions, definite rules on what is and is not allowed. But as long as sub are part of the equation at all, it is not a level playing field and never will be. And personally, I don't see anything wrong with that, because it's better than not giving the userbase an opportunity to participate at all.