He's not that bad a player, it's just we are horrendous at profiling players and working out what we need, even when it's blindingly obvious to everyone outside the management.
We needed someone to lead the line and score goals, but as we all know, Zirkzee isn't that kind of player and never has been. Gyokeres was an obvious choice, but we were never interested.
Talent wise there is definitely something there so maybe under the right manager and with a bit of patience, he could still be a good player for us; but the absolute clown show we are right now makes it impossible to make a fair assessment of him.