Personally I think it's a series of possibly unintended coincidences being magnified by 2.1 into something that has become the only viable medium ship choice for PvP.
The FdL as originally designed and released had a great base shield modifier but a gimped powerplant meaning that it couldn't even fit 6 boosters except running all cannons, and hence couldn't maximise SCB's, and also had awful pitch. Because of the power issue, its utilities were pretty much for show or PvE in those days, beyond double chaff.
Now it has good pitch, the powerplant of a Clipper, the ability to fit all the best weapons and all the boosters at the same time, and utilities have become the king of all modules by reason mainly of heavy duty boosters - which magnify the base shield modifier. It's the powerplant facilitating the weapon and booster stacking that is the real issue.
The powerplant can't be changed now (and could be modded back up anyway) but the stacking of an OP utility needs to be dealt with in some way.
The ability to attack or in other ways balance against heavy duty boosters seems to me one way of dealing with this combination without directly nerfing the FdL itself.
Alternatively of course FDev could just dial back on heavy duty boosters but I have yet to see them mentioned - why no diminishing returns? Heavy duty boosters pull the teeth of the PA buff.
Even if booster stacking is dealt with, utilities will be like gold dust so long as emissive and missiles are so strong after shield drops - a four utilities ship struggles to cover all the bases.
Other medium ships such as the Python could therefore be considered for an extra couple of utilities. But this has been suggested for a while now and nothing has happened.