My group's story may be relatable...
My regular daily crewmate and I have always embraced every aspect of the game. We began our journey grinding PvE and tolerating PvP. These days, though, we absolutely love engaging in PvP and playing the hunter. The PvP part was an "acquired taste"...but once we really embraced it and treated loot like a cherry on top more than a requirement to our session, we absolutely fell in love with the PvP aspect. Thousands and thousands of hours in, we both still love it and lean more heavily on the PvP side of the game now.
That said, the rest of our group abandoned the game for similar reasons to your friends. They didn't embrace PvP, loot was the only reason they played, and they were sick of having sessions sum up in a "boss battle" against another crew where you had nothing to gain and everything to lose.
My regular crewmate and I had been sprinkling in tales of our battles and triumphs in our group chat. The glory. The laughs. The losses. The intensity of the great battles.
Then, we got them to bite. We said let's just do a session where we play the hunters. We'll collect loot along the way, but we're not doing any voyaging or world events. We'll just hunt Emissaries and have some laughs.
We had an absolute blast. Lost some battles, won some battles, laughed a ton and engaged with some other crews along the way with some laughs and grogs.
A couple sessions of that mentality and playstyle and they were in love all over again (they're all founders). I'll never forget after that first session, my one buddy was like "holy $&-@ SOT is super fun again!"
Now, when we all hop on to game on a Saturday night or something, SOT isn't the last choice, it's the first choice.
Take what you want from that story, but if you treat SOT as a PvE game and loathe PvP, then I don't have hopes for your friends ever enjoying the game. PvE in SOT is incredibly easy and monotonous. It's like powerwashing simulator...satisfying. It's only a fraction of the game, though, and you have no control over when the part that's actually challenging (PvP) is going to be on top of you.