I think it's open for interpretation to prevent teams from just camping in the pitlane to make adjacent stops more difficult. A headfake can just as easily be interpreted as a change of plan, and in the case of Lewis chasing Max, there were multiple changes of plan. The team has to be ready before the driver turns into the pit exit, in order to minimize time on the stop, so if they tell the driver to stay out one more lap at the last minute, it's going to result in what looks like gamesmanship. It's really hard to interpret, and it would be stupid to officiate that you can't leave the garage unless you definitely stop. That would ruin many on-track battles.
I think the rule is fine as is, because you don't hear teams whining about it. When it's only a few disgruntled fans complaining, then it means the rule is fine, because it gives the stewards the right to punish the blatant attempts at sabotaging another team's efforts, while allowing some cat and mouse to play out both on track, and in the paddock. The rule isn't designed to prevent cat and mouse games, it's designed to prevent out and out foul play. If anything, I think Mercedes had a stronger case against them a year or two ago, when they setup completely next to Ferrari, causing a slightly slower stop, while not pitting a car. I believe they pitted the next time around, though, which probably strengthened their case, but that was a more appropriate time to complain.