I personally PvP for fun but the marks of honor are nice for experimenting with new types of gear and outfitting secondary ships. PvE dailies for me are like chewing glass. I think they may be there to make a PvP 'career' a viable option.
Sadly the majority of Feds I see are just there for the dailies/accolades, so they die really fast then complain on the forums that Klings are overpowered
Those accolades go pretty far though, and people might get impatient. There are multiple levels. I'm working on a PvP accolade to complete "Raze Enemy Headquarters" (Klingon Cap and Hold daily) 70 times after I completed the accolade for 35 times :/
It hurts PvP but I'd still rather have them both in there (not that I care about accolades).
I think on all 4 of my toons I have multiple digit honour points and a handful of explore stuff.
I don't hate the explore stuff.. I can just live with doing one round a week.
For me real people are much better opponents then the ai.
The people playing for marks come in waves... they play until they get what they want then they stop.
I notice these days even the fed pugs consist of the same small handful that seem to enjoy PvP.
As a note I have noticed the fed pugs in general have gotten much better the last little while. You still end up against the odd group of recent RA feds... just not constant like it was at one time.
Without those players, PvP would be way, way below critical mass and nothing would EVER pop.
As opposed to just being slightly below critical mass and popping unevenly and inconsistently.
So they are kinda necessary, on t he other hand with thigs like Open PvP and smaller map sizes, it might go away.
But I think another factor might be that the marks for PvP really remind new players "Hey, you can do PvP. it even gets rewarded". How many players might have gotten into PvP and stayed there for an incentive like the Marks?
I think it probably helps more than it hurts in the long run. I started PvP because I got bored with PvE and this is where the good items were. I stuck with it even when things were tough because of the rewards and then once I got with a better bunch I started to enjoy it more. Now I do the dailies for the marks as much as I can, but I'm usually right back to the arenas when the daily is done.
I feel like the marks are a nice carrot to dangle in front of the people who might otherwise ignore PvP. Unfortunately, they are also the reason for the Runabouts and Shieldless ships floating around. It really is a lot more enjoyable when people consider the prize after the fight, not during it.