I am a firm believer that they both serve a purpose.
In my younger years I spent plenty of time and miles on the PCT here in Washington. I would not even think of a bladder back then, mainly because technology had not caught up to the bladder filling process using a filter. These days bladders can be filled using specific filters or adapters which make it easy. Bottles were always the way to go (still get the nod for me). When bladders first came out many of them were made of materials that just flat out made the water taste like you were sucking on a balloon (not anymore). As bladders have become more and more technologically advanced I find that for months out of the year (spring and summer months) while scouting it's all I use primarily because I am moving (hiking/ATV) from camera to camera, checking video or photos, covering miles of country and exploring new territory, sometimes with limited time to get it done. I just love the convenience of drinking on the go without having to fiddle with a bottle. Bladders have a bit to be desired when it comes to rationing if you ever find yourself in that situation as most of them are in a closed pack and you can't tell how much water you have unless you make a concerted effort to stop and check so I don't like them for that. If you ride an ATV for any distance in the backcountry to and from hunting areas bladders are far more convenient than water bottles as you can drink with a helmet on. Bottles still get my nod for backpacking, or multi-day trips of any kind. The utility of a bottle/bottles is unmatched. Bladders get the nod for anything "day" related. Bottles always get the nod for multi-day anything.
My .02