1) If you're an LP and you think this type of thing is a really big deal, don't put your money in a fund that does it.
2) Even if they didn't invest in themselves, they could just as easily give your idea to a more competent entrepreneur and invest in her instead. If you're really worried about your proprietary idea being stolen, you shouldn't be in these meetings.
Sure. But I think the author's point was that he does find these concerning, and that other people (LPs and entrepreneurs) might also find them concerning if they were more aware of them, and that he thinks that VC firms should institute rules against them.
So yeah, you can totally have the perspective that those two points don't matter. I'm not saying that you should think that they matter. But some people do think they matter, and I don't think it is wholly unreasonable to feel that way.
My goal with my earlier comment wasn't to make you agree with the author. It was just to point out that the author's points aren't just about "fairness": they're also about whether VC firms are best delivering value to LPs.
On a nitpick point: I never said "idea". The idea that people are worried only about "ideas" is silly. There are other things to worry about: if you're raising a series B and are providing data about your business, that data potentially has concrete value beyond merely an "idea". I don't personally think it's at all unreasonable to be concerned about people misusing that data.
2) Even if they didn't invest in themselves, they could just as easily give your idea to a more competent entrepreneur and invest in her instead. If you're really worried about your proprietary idea being stolen, you shouldn't be in these meetings.