Boss Mechanics have become more complex, and there are just more of them in a fight. Although players have gotten better, there are more resources available to them, gear itemization, better talents. It's hard to gauge, but in my opinion the game has become more complex boss mechanic and rotation wise and less tedious attunement and grind wise.
Man if I played back then with my skillset now and real addons it would be a cakewalk.
And once again we come back around to the same old argument.
"Slower" and "more tedious" do not necessarily equate with "harder."
OMG 13:37 - Then Jesus said to His disciples, "Cleave unto me, and I shall grant to thee the blessing of eternal salvation."
And His disciples said unto Him, "Can we get Kings instead?"
Sadly, the nostalgic don't want to accept that Lumineus.
I also find it incredibly amusing how "former top raiders" or "back in the day i was an ace, brah" comments come from people that admittedly don't raid heroic these days or haven't since Wotlk, Cata, whatever. Yeah - really valuable empirical data isn't it. Comes right back to what I said pages ago - too many youtube raiders and hearsay town criers.
Just play it for yourself, and stop jacking off to your own glory days.
Legendary cloak is harder and takes more skill to get than atiesh in classic.
Legendary cloak takes like 4 months of errands but any idiot can just kill bosses in naxx40 and usually finish his staff in less than 4 months.
It's the same as BC. You do 5 mans for badges that can get you gear on par or equal to the raids that you will be doing. Only in BC you also had another option of spamming AV, getting honor for an entire day, and just buying welfare Merciless gear and raiding like that, and still did as well as the next guy in full PvE gear. Content and mechanics wise, not really, they just add more stuff to avoid, and attempt to complicate things more than they should.
I like how implying TBC wasn't superior in every single tiny little aspect is enough to just blow some people's minds.
Fights more complex, more abilities, priority dps instead of pure memorized rotation... More players are better however, so any increase in "difficulty" is effectively moot for the most part.
Looking at the question of whether or not the game itself is harder, if someone from BC played right now, yea they'd have a hard time.
Back then people heading into T5 instances had just enough gear to beat T4.
Now people heading into the new raid (normal/heroic raiders) have full gear from the previous tier and are probably nearly fully geared from it with item upgraded, reforged and gemmed gear.
I guarantee if they held tier 5 off in TBC and released one raid at a time (remember most people worked on SSC and TK simultaneously) then most people would have downed bosses quicker because they'd be fully geared from the previous tier.