I think one of the biggest issues with raids in this game is failing nets you nothing. This game trains you to focus on metas/activities where there are plenty of people, and to either follow the crowd or create the crowd with little individual accountability. Players can't stand doing an activity that rewards nothing. In fact I've bumped into players who just can't admit that they didn't do the right thing in a meta - I zoned into a ley line anomaly just before failure where there were no less than 20 people and someone was saying the other time slot was better due more people in the other time frame. I'm pretty sure I've done it with 10 (or low teens before). This basically means players try raiding once and give up, without giving it a second thought.
I actually think this game needs to encourage PuG raiding to encourage players to learn some form of accountability and team work. In addition to the fact that it will help keep the raiding community vibrant. And I think I have a solution to do just that.
It works like this:
There is a new weekly objective for each boss in one wing (rotating between wings), giving 5 AP, 5g, 1 bosses' worth raiding currency for ascended gear and 1 LI per objective. This objective isn't based on the boss actually getting killed. It's based on dealing total damage to it that would have been fatal if given in one go (as a squad, all of the damage of any squad you participate in counts toward your objective). The reason for this is if attempts alone are rewarded, people will just fail fast. So it has to be performance based. This will encourage players to put their best foot forward. Adding one objective per boss also encourages people to try the next one if they succeed or to pick it up later. I don't think this is game breaking -> consistent raiders earn way more of those things (except AP, which they would get anyway when it's implemented), so they're not being slighted at all. It's a performance based participation award, everyone wins. Honestly, the rewards just aren't there for strikes and most people wouldn't want to do something hard on that level for no reward (and by hard I mean wait in an LFG group forever).
Also note, this isn't giving away any of the legendary raid gear for free either - the armor and the ring are locked behind collections tied to boss kills. It's just giving the community incentive to try.
I would also recommend showing the objective clearly, above dailies in the UI, along with a recommendation for using the LFG tool (so newer players get accustomed to it fast). This way everyone knows it's there.
I know this will make elitists cringe because they don't want people pugging them, but the reality is GW2's structure is very open group everywhere else in the game, so encouraging that in a raiding environment can only ensure more community participation. Raiding will never be mainstream if LFG PuG groups aren't capable of doing them and there isn't guaranteed incentive for them. Period. Also CM mode is there for people that want something harder anyway. PS I PuG normal difficulty in WoW too and it is PuGable.