Probably sounds a bit like overkill to many pilots, but it's one of those box ticking exercises that ATC need to make sure they've ticked to avoid getting hauled up on something easy at a later date.
As has already been stated, you may well have given it when you check in but we are on the phone a lot of the time, whether to radar, airport authority, other position in the tower, etc so we don't always catch everything that's said. No doubt it's annoying, but it's just one of those things. Just like when we give an instruction and it's not heard by pilots as you're probably busy doing checks or speaking to your handling agent or company. Just one of those things.