I do think that most people concentrate too hard on feeding anemones hunks of food, but to say that they get 99.9999% of their energy (food) from strong lighting is not quite correct either. lighting will only feed the zooxanthallae which will only produce sugars. Anemones need proteins (meat) also.
I also rarely "spot feed" them but i do feed my tanks/fish heavily enough that the anemones are sure to get small portions quite frequently. When the gut contents of anemones have been examined, its usually small "pods/crustations" that are found.
My anemones that rarely get spot fed, but do get very small portions/left overs often
S.gigantea #1.. 14 years and still strong
S.gigantea #2.. 3 years and still...
S.gigantea #3.. 3 months and still..
H,mag....... 3 years and still....
BTAs(E.quadricolor).......... 9 years and still..
LTA (M.dorensis 2 years and still