Myth 1 = hiking boot equals heavy. Not so! There are plenty of light-weight summer walking boots on the market and plenty of mid-weight boots with strong mid-sole support made out of modern water proof materials. Much better options than volleys.
Myth 2 = Lighter is better. Not so! The heavier the load you carry (including person and pack) the
stronger, more supportive the boot needs to be (you don't bush-bash with low profile radials on a loaded 4WD, you just don't!). Heavier doesn't necessarily equal stronger and more supportive, but lighter can mean a compromise.
Myth 3 = Ankle support means rigid. Absolutely not! A good boot will allow plenty of forward movement while "supporting" lateral/anterior flex to prevent ankle strains and sprains caused by sudden stretching of the muscles or ligaments when stepping on uneven surfaces. (I shattered my ankle badly when I was 25 and I couldn't walk more than a 100 metres in any boot that held my ankle rigid).
Myth 4 = More ankle/foot movement means less knee strain. No. Walking with moderately heavy or heavy loads and poor arch support can lead to overpronation, which is an excessive inward roll of the ankle and foot while walking. This puts extra stress on the lower body and can lead to knee and lower back pain. If your back hurts at the end of a days walking you have a problem with your gear.
Myth 5 = All hiking boots are the same. No way! There is endless choice. Just because it is labeled 'hiking boot' does mean it is good to walk in, or good for you to walk in. IMO you need to find a boot that feels good on your foot and doesn't pinch or rub or squeeze. If it rubs, pinches or squeezes in the shop it will do the same when you walk. The boot should hold your heal so that there is
no heal lift when you walk (rub = blister). You should have the option to tighten the bridge lace before descending to prevent toe jamming (ie. the boot should hold the foot). I also prefer a water-proof tongue and good mid-sole and arch support. If you tried one pair of boots and didn't like them, then shop around until you find a pair of boots that suit you.
You only have two feet and you need them both to walk. Ankle injury, both from sprains and from bashing on rocks and roots, is one of the more common walking injuries. When you are two days walk from home and you have injured your ankle (seen it done) it won't help to wish. The scouts have a saying about this - Be prepared! But who listens to the Scout Master.

Eh Corvus!

(IMHO) one should choose the right boot for the intended job; a boot that will support your weight and the weight of your gear in the worst conditions you will experience on your walk. If you are luck you might afford two pairs of boots (summer and winter), if not then choose wisely.