This one is a bit of an eyeful, so be prepared for a long post. I recommend reading the whole thing, but there is a TL;DR at the end.
If my memory serves me well, this will be my biggest post since joining the community team! \o/
Mírion has hit the nail on the head in pretty much all of his posts in this thread so far. Rated PvP has been seeing a decline in participants over time; however this is not because of balance issues as most people assume it to be. It is mostly due to the increased separation and distinction between PvP and PvE gear. As has been said, getting a full set of PvP gear is not really that hard in the sense of difficulty, but it is when you consider the grind and the feeling you get in those first few steps of PvP without the right gear.
I am sure that most, if not all of you here have at least once had the experience of entering into PvP either late in an expansion or season. If you have, then you know how difficult the process of getting your honor set and first few conquest pieces is. You start off by getting hit by trucks and attacking back with the damage of a wet noodle, as your gear gets better though, the experience improves and you start having fun. But you have to remember that it's those first few steps which are the most crucial to people continuing their PvP experience.
This separation of gear has caused a decrease over time in the number of PvP participants because the first few steps into PvP are so daunting for those who try it that the turnover results in a drop rather than an increase. For PvP, because so many people get scared away from it when they first have a go, you have much less "fresh blood", so to say. This ends up resulting in there not being enough new players sticking with PvP to compensate for those that decide to move onto something that is better suited to them.
Let's take two examples of people who are taking their first steps in PvP right now and making their decision if this is something they want to keep doing:
- Player A is an established raider. They’re geared out in some pretty sweet ToT items, but wants to try out something new.
- Players B is a freshly dinged level 90. They’re keen-eyed to try out PvP and has their crafted PvP set.
- And to have them here to be used in the two below examples, Tyrannical, the BiS PvP geared player having a bit of fun in battlegrounds.
Now the below scenarios are extreme cases, you will not always be coming across a BiS person in PvP, and there are ways in which to increase your enjoyment when starting out such as playing with friends. While a lot of players will push through this initial hurdle and start to enjoy their time in PvP, I just want to give you some examples of what a first time experience can be. Epic storytelling time #1:
A enters an Arathi Basin match, bright-eyed and keen to try out this aspect of the game that's entirely new to them. The gates open for A and they charge off to Lumber Mill and engage their new-found foes. They are having a jolly time doing some decent damage and even scoring a kill while no one is attacks them, however then Tyrannical on the opposing side decides to attack A and he dies in an instant. A wonders what happened, but ignores the occurrence the first time.
A resurrects at base and heads out into the battle, but the same thing keeps happening — A goes into battle, gets attacked and dies. They get tired of this happening repeatedly and decide that PvP is not quite their cup of tea.