Why would non-PvPers be touching Frontlines in the first place? The majority of them seem to think PvP has no place in a Final Fantasy game anyway, I doubt they'll be trying it out regardless; most of the ones I came across in General Discussion were frankly completely ignorant of PvP and were only agreeing with no Morale because others were.
I really don't get it, doing away with Morale makes it a level playing field? No it doesn't. Doing away with Morale just does away with one of PvPs key sense of progression; obtaining new PvP gear. With out a stat differentiating the two, PvP and PvE gear are identical. You still have players that are better than others, and not because of their personal skill. You have players who've earned more AP and thus fire off their PvP skills more often and for greater effect, as well as boosting stats. You have players who are different races (highest VIT to lowest VIT was an 8 point difference I think). Even with an i80 cap you'll probably end up seeing players with different gear, if they set it to i90 instead like they've talked about, then the person who buys and melds crafted gear has the advantage.
The only issue Morale brings is when it is a significantly higher amount of Morale. Like I've suggested, they can solve that issue with a buff. How will they be solving AP and racial differences? They can solve gear differences by just making a standard set of gear you aim to obtain when doing Frontlines. I'd say i70 PvP gear would fit that slot nicely, worst case they just need to make a few adjustments to Wolf Marks to ensure that isn't such a daunting task. Honestly, i70 PvP gear should just be handed to players as quickly as possible, then the difference in Morale is laughable. Giving people without any PvP gear a buff that provides Morale is a great way to completely remove any issues before they obtain the gear, and it's hardly a difficult thing to do.
Oh, and before anyone bothers, the AP difference will not be solved by the queuing system. You can already group a Rank 40 with a Rank 1 to balance their Ranks out and get them into matches faster; Frontlines has a lot more freedom in that regard. Being 24v24v24 there is a lot more room to balance out a teams Rank, there is a lot of potential for higher Ranks to find their way in and have an advantage because of it.
Personally, I don't mind the concept of people having an advantage, because I know (or hope) the teams will be balanced. If Team Maelstrom has a few high Ranks, so will Team Twin Adder, and Team Immortal Flames. That's also why I don't mind the concept of Morale playing a part, seeing as Morale gear is pretty much tied to your Rank, with the only advantage being "I won more rounds, so I got the gear while being a lower Rank than you".