Is it Snowing ?
It must be snowing, I see a special snowflake,..falling from the sky.
There have been 'catch up' systems in place in this game since the end of TBC, the Isle of Quel'danas had a limited catch up system built into it, and if I remember correctly all the so called 'Hard core' Raiders went nuts then as well, it kinda went like this -
"How dare you Blizzard, how dare you, how dare you give epics to those who have not sacrificed their entire life to a game, betrayal Blizzard, betrayal we say, and therefore we now cancel."
Childish in the extreme, but then the special snowflakes always are, and always will be, seeking to restrict all other players who are not prepared to spend 24 hours sat in front of a PC playing a game, seeking to dictate what others can have, in reward for time spent, seeking to gain status from epics. lol
Vanilla - No catch ups, guild had to boost you, carry you, no easy skips, nothing that I can remember anyway, so could be wrong.
Early TBC - No catch ups or skips.
Late TBC - Isle of Quel'danas, Blizzards first attempt at a catch up system, for a guess this is when Blizzard first started looking at Data regarding how many players were getting to see end game content.
WotLK - Had a catch up system put in place outside ToC, in the form of a vendor who would sell you an entire T set for justice points. (or was it valor, cant remember)
Cata - Had a catch up system in the form of some fairly easy to get Valor gear that was very good, valor cap was higher back then, all easy to get.
Panda - Timeless Isle
In short, Blizzard make the game for everyone, not just the elite, and they understand that a lot of people jump into expansions at the end, they don't play the whole period, plus they understand that not everyone can sit in front of a PC for 24 hours and not see daylight for 6 months.
Why do Blizzard think like this ?, because it makes lots of money, and it's the correct way to think, simply because it's just a GAME, AND EPICS ARE JUST EPICS, they don't make you a better person, no really they don't, they are just,...purple pixels.