Force fields is fine. The things that it provides, defense and mez protection, are extremely valuable, to the point that people devote entire billion-inf IO builds and incarnate slot choices towards chasing them.
FF is very specialized. It shines in the low levels before player defenses and controls have fully matured, and on teams with poorly-geared players, and that's fine. Not every powerset has to be a generalist that buffs, debuffs and heals; it's alright to have some sets that shine in certain kinds of teams, just as some sets and AT's are more suited to team or solo play.
The proposed changes to give FF bubbles defense debuff resistance and absorb are poorly-justified:
Nobody ever complained that FF bubbles are not protective enough. They are among the best defense shields in the game, and one of the few that can be power boosted, so why further increase their protective value by giving them absorb and debuff resistance? Is taking people to the incarnate softcap not good enough for you? FF's role is to protect the team, not make them invulnerable.
Defense is common, easily gained, available in larger amounts than resistance, and is not capped by AT mods. In exchange for these tremendous advantages, it is easily lost (except on specialist defense-focused armors) and countered by tohit. Allowing FF to apply defdebuff resistance risks further unbalancing the softcap meta by making extremely durable softcapped characters even more tough. If they want defdebuff res, make them take ageless radial and give up their precious barrier they depend on to softcap.
The stated rationale for these changes is to make FF more attractive to players already decked out in set IOs. But we've already established that not all players are stuffed to the gills in IO sets, so why does it matter what they think?
FF's only issue is that it has too many gimmicky powers with extremely niche uses. If you really want to make some changes to FF:
Vastly increase the DPA of force bolt - it should be among the best Defender blasts
Increase the DPA of repulsion bomb
Make Detention Field a toggle so you can detoggle it, to release the affected enemy to be killed when it's safe (no need to wait for it to fall off just to avoid leaving a dangerous enemy at your back, or stragglers in a defeat all)
Add pulsing damage to Force Bubble
Rework PFF: remove only affects self, reduce resistances or change to absorb instead - make it a defense that's practical for the bubbler to use under heavy fire, that doesn't compromise their ability to defend the team or reduce them to thumb-twiddling
These would actually benefit FF by removing mechanics that force them or the team to wait around doing nothing, and add blasting as an alternative gameplay style for when defense shields are less needed.