I think the proposed value here is in the quality and quantity of protein provided

Boiled Lentils are around 9% protein - http://ndb.nal.usda.gov/ndb/foods/show/4783?qlookup=16070&ma...

Where according to this thesis project presentation grubs are 42% protein.

I was puzzling over how 25% protein could turn into 9% protein, but then I realised: that boiled number is including 70% water. Obviously there is no protein in water.

If you ignore the water, it's 29% protein. Alternatively, 25g/100kcal.

Lentils don't agree with a lot of people due to taste, texture and/or flatulence.

However, the people who don't eat lentils probably wouldn't touch ground insect meat either.

Aside from the other points made here, many bugs are ecologically cheaper to produce per unit of nutrition. A quick google brings up a (probably biased) article:

http://www.rainbowmealworms.net/blog/why-we-need-to-eat-bugs...

I used to have some other references that were a bit more scientific, but I can't seem to track those down.

An excellent question, I hope someone weighs in.

And have my teeth rot from all the phytic acid?

Umm what?

You're supposed to cook lentils. Also, turns out lentils don't even contain that much phytic acid from the start.

Finally, your teeth rot? How? I suppose if you didn't cook the lentils, you might want to chew and ruminate them in your mouth for a few hours (tip: no, you don't), which might be long enough for the acid to have some effect on your teeth. But if you consume them like normal, and apply some basic dental hygiene, you're going to have to explain to me how this could really affect your teeth worse than most other foods (which are usually also slightly acidic).