I'm a regular reader at Fel Concentration and love Poneria as she is my unofficial official arch nemesis warlock person. (GO MAGES!) And apparently she's in the middle of a debate about BOAs with another blogger about the merits and flaws of the items in game. I thought I'd offer my own humble opinion. (Yes, mages can be humble.)
When BOAs first came out, I was excited. I had my first 80 and plans for another. I still think they're a great idea, although not necessary. Some things to note about me: I have 4 80s. All of them are raid geared to a point that they can perform decently in ICC, 2 also with off specs that perform in ICC. I LOVE end game. I love raiding and purpz and min maxing and high dps and Pew pew. I hate questing in old world and playing Horde makes that worse. The Barrens is the bane of my existence. The last character I leveled to 80 was leveled almost entirely in the RDF system, with quests related to dungeons up until 70 where I did a daily for my badges and did streamlined quests in the first couple zones of NR. I have exactly 0 characters with lore master. 2 have explorer because of the holiday crap. My main raiding character can't help with summons outside ICC because she hasn't done the quests.
So I guess what I'm saying is that I did the journey from one to 80 4 times, and the same from one to 60 several other times. It doesn't hold the thrill for me any more. So BOAs are my best friend. I get to 80 and I replace those suckers as fast as I can in dungeons and quests. Do I think BOAs keep you from learning to play your character properly? No. I think people can level to 80 with BOAs and without BOAs and not learn how to play their character properly. Please note that my "properly" is that the player understands the mechanics behind the abilities they are given and can perform their role in a way that does not affect the roles of another player. IE a hunter using distracting shot because it's extra DPS, despite pulling aggro off the tank is not a good player. Or a Resto shaman putting earth shield on themselves so they can concentrate on healing the others, despite taking little to no damage. Or a mage putting 71 points in the fire tree. Or a DK tank trying to tank in Blood Presence because "lol it dus mor damage and I heal myslf so u dont have 2". Make no mistake, I have seen all of these people. Most of them at level 80. Using a BOA will not save you from having to read the tooltip. I'm not saying you have to minmax your gear from level 1 on to be a good player, but yes, I do require some basic understanding of your class and role.
So what about ruining your experience? Just how many times do you have to experience Scarlet Monestary to make that quota? In the BOAs I used on my shaman and leveling her on the RDF, I must have killed the bosses in the wings of SM at least 30 times. That's more than enough Scarlet Crusade for my tastes.
So besides that, a lot of the gear dropped in old world and BC dungeons and quests is like "WTF why is there agility on my cloth?!" Sure you can make the best out of it, and you likely will with only a few current available slots for BOA gear. I haven't gotten myself a ring yet (stupidfishing), but my collection includes the PVE staff, healy hammer, and 2-handed axe, the PVP 1-handed sword, mail caster shoulders and chest, cloth shoulders and chest, and plate shoulders and chest. I will quite possibly be purchasing leather melee and caster gear, as well as a weapon appropriate for a druid. I also have both trinkets. The nice thing about the RDF system is that the reward bags you get once a dungeon give you a piece of loot that's hopefully appropriate for your class. They also have made the gear with viable combos so there's no agility on your cloth. Blizzard even went so far as to update some of the gear in old world so it wasn't quite so stupid. Still, it's one less slot you have to worry about, and even then sometimes you might find something better, so you unequip it for now and put it back in later so you don't have to struggle to find something to fit that slot when the piece you have their is 10 levels behind.
They save you money too, if you think about it. Often the good stuff that's crafted or BOE is up on the AH for ridiculous prices. Twink ecomonies still exist. So you can filter that money instead into trade skills.
Speaking of trade skills, sure they get behind. I didn't get my skinning and leatherworking for my shaman up to Northrend levels until after she was 80. It interrupted my fluidity with trade skills, but getting to 80 faster meant more time later to catch up when I was doing other things. Plus I have some great friends that pitched in to help. And I also hate leather working and am fairly sure the Devil had his hand in it. I can remember when I was leveling before BOAs and I still got ahead of my trade skills unless I made a conscious effort to stop and gather and combine. But at least I have cash to use on them this time around!
I wouldn't mind if they made BOAs a little easier to handle. I read somewhere a while back that you could mail BOAs across factions, which is fabulous, but I'm not sure I believe it and I haven't had the guts to test it yet.
I'm not going to be a snot and say that if you don't use BOAs you're a terrible player, because we were all there once. It's a personal choice. You don't have to like it, and it's not about being better than people who don't use or have the option. It's about getting to 80 faster so you can do other things.