I will be honest 4 man feast and fold intimidated me. I don't even know why but it was just intimidating. I think part of it is playing with randoms and lack of confidence in my skills. I did play 4v4 ranked team during season 4 but it was hard to get all 4 of us on at the same time and we were going up against platinum players (3 person team) who would pick up 1 random person. For a fresh team still bronze going up against a platinum team was just.... well not fun. So I stuck with Frontlines to boost my skills and confidence which it did. But when Season 5 came out I was less inclined to participate because I prefer astro and I heard it was not as strong. I am sure I would survive in feast but there hasn't been any real reason to do it as I honestly don't care about glamour.
But what was appealing about Frontlines in 2.x gear progression and even 3.x is I enjoyed it for the group play. I would group up with friends and we would have me and my gf somedays to having a full group of 8 and even running 2 teams (we would end up head to head). This is what was appealing to me.
I remember once we had a ninja from another server end up harrassing us until she joined us in our base stealing. She was blown away a group of 8 people held off a full alliance at their base. We won the match off of kills. She thought we played cat and mouse but when she got 13 kills at the end of the match with 1 death she was sold.
With the 4.0 release the semblance of pvp has significantly diminshed. People may call it Nostalgia but I was not one of the ones on her complaining. I would get CC locked but I still enjoyed it and I wish there was something more than Carbon Copy Glamour items to actually go for (Garo and other sets looked unique). Making it accessible from 30 on for one queue is actually making it less appealing to. It was my end game in 3.0 and will be my end game in 4.0 but people leveling are just using it as a means to an end to get the PvE end game which is counter productive to the PvP community.