I spotted this thread a week or so ago and thought it was really good question, so hats off for asking it and apologies for being so late.
For my part, and it has likely already been said, I joined GC Disco because of the RP appeal. Now part of that appeal certainly came from the potential of PvP, and it was exciting. I did learn a few things about the game that overall lessened my interest in PvP (although did not destroy it).
Firstly, and almost certainly the biggest point, is ping. I'm from a small nation at the bottom of the world with less than ideal internet connections. Fast paced PvP combat with multiple players running and gunning is great fun, but it was a hell of a strain on my internet as well as my older laptops that I started playing on. I joined BAF| and took part in big fleet engagements and snub fights and all the rest of it and it was grand. Sure I was shot down but that was part of it and I look back fondly at the time I saw @Thunderer s assessment of my PvP skills ''Still a disaster in fighters, might try him on Caps''. Much to his disappointment, I was a disaster on them as well, but I found my niche on Bombers. Now I did try to learn PvP, and there were many people who took the time to try and teach me how to PvP @Gagadug @Wesker @Sombs @Thunderer and @Backo among many others. It wasn't all a waste, I won my fair share of punch ups and did develop my skills in a fighter as well as caps.
But then again, I loved RP (and still do). The line @Kaze gave me once was ''This is a space sim, RP needs to be backed up with PvP'' and while I raged against that statement for admittedly far too long, he was quite correct. RP was a personal choice, but PvP could and did sneak up on me (often when it was the most bloody inconvenient). I was put off by some players jumping me for no apparent reason, unfairly ganking and generally just being little more than bullies because they could. Yes, it happens and that is hardly a reflection of PvP overall, but it did put me off, or at very least, it put me off dedicating the time and effort necessary. I'm aware that I'm coming across as a bit of a snowflake and that's alright, I probably was. But I ceased to enjoy the game when faced with those players. So I made my return to RP and found it far more enjoyable.
Now don't get me wrong, I enjoyed duels and fleet engagements, I loved being amongst it and dropping ASURAS shots all over the joint or being a scout (something I soon learnt needed a bit more skill than simply flying up the enemy fleet, getting blown up and then reporting their position, eh @Gagadug ?) But PvP as a reason to log in? No. Not my cup of tea. But RP has a way of draining one as well, in a different manner and form. Eventually I tired of Disco altogether and took my leave, at least for a little bit. By now my skill set has been entirely reset to 0 and I'm back where I started. Maybe I'll make another go of it, but as it is I'm quite content to learn slowly and steadily, rather than fly guns blazing into a fight without the faintest idea of balance, techcells or any other facet of PvP, I'll pick up what I pick up in due course. PvP to me simply isn't the be all and end all of Disco, nor for that matter, would I want it to be.