I didn't say that the safe operating area is not a limitation with MOSFETs, just that it's generally better than BJTs, especially at higher voltages.
I had read your post as: "MOSFETs are better than BJTs", which isn't to say they are perfect, just that they are less bad.
I suppose it's still good to make note that a beginner might read it and say "MOSFETs are flawless", which would be a mistake on their part, but one which can be avoided if the matter is emphasized.
For anyone keeping track: all transistors suffer from 2nd breakdown, it's just a matter of "how much?". IGBTs are categorically the worst, not being suitable for DC operation at all (at least at any useful voltage). BJTs are better, but it depends on type. MOSFETs are better still, but it again depends.
The root cause is too much power in too little die area, and an unfavorable tempco that causes hot spots and runaway destruction. All devices suffer this, but designs can be made in such a way that runaway falls beyond the power dissipation limit.
You rarely see 2nd breakdown limitations on very small devices -- SOT-89s and TO-220FPs, say -- because there's not enough power dissipation in the first place to get into the runaway region.
Lateral MOSFETs avoided this by being such sucky designs in the first place -- such low power density that there wasn't enough temp difference across the huge die to get close.
BJTs have long been made in two styles: those for linear operation, and those for switching. (There are other differences, making the switching types even better suited for switching; this is a gross simplification.) A typical linear example might be a part rated 250V, 20A, 150W, with a small derating (due to 2nd breakdown) above 150V.
In contrast, a switching part might be 800V, 20A, and 100W but derated sharply above 50V. At 200V, the linear device might handle a full 100W still, while the switching part must be limited to a couple of watts at the same voltage!
Paradoxically, the newest generation of high voltage MOSFETs (SuperJunction type -- if the datasheet headline doesn't say SuperJunction, CoolMOS, QFET, MDmesh M2 or other trademarks, look at the capacitance curve, which is distinctive: Coss tanks above 20-50V, then rebounds slightly at high voltages), despite having higher power density than ever (more amps in less die area, while still handling high voltages -- and high voltage * high current = super high power). I guess the difference is in tempco. That or they're all lying...
Tim