Since launch, stealthing into and out of fights has been broken. Every attempt to "fix" it with counters has proven almost pointless. The mechanic needs to get removed. It irritates pretty much everyone but the trolls that run it. Either stealth before or after an attack not both. Reveals need to be long and they should have no counter. I am fine reworking the handful of traits that revolve around this mechanic. Thieves already have strong evade and movement... I even play a variety of no-stealth builds with success.
This last mark counter was only needed because Deadeye had the ability to remove reveal. The mark mechanic is overly complicated manure for a junk stealth mechanic. Many of the serious thief nerfs over the years track back to balancing stealth. Instead of several weapon sets that work well with dynamic play, most are pigeoned into D/P, Rifle or both.
Tweaking stealth so it is an opener or escape rather than both will go a long ways towards removing one of the most crappy WvW mechanics this game has. Oh and yes, I mainly play a thief.