The fact is that credible pension funds don't make their money by competing with sell-side firms. When your only job is sporadically making large block trades, you're happy to see spreads competed down as far as they can go. You don't care which market makers are winning the race to provide the cheapest possible liquidity.
Claims that buy-and-hold funds are victimized by HFT are hard to square with what Vanguard said, and with the logic of how automated trading works.
Long term investment might be a better strategy than wild speculation for a goal like that.
EDIT: Replying to my own question: http://blogs.wsj.com/law/2014/09/08/law-firms-sue-stock-exch...
http://en.wikipedia.org/wiki/IEX
"IEX's main innovation is a 38-mile coil of optical fiber placed in front of its trading engine, which adds a round-trip delay of 700 microseconds and is believed to limit traders' ability to respond on the dark pool ahead of IEX's own pricing algorithms."
They still allow collocation, venue arbitrage, and non-human timescale trading. Any electronic trade you could do on any other dark pool you can do on IEX.
The main difference between IEX and other dark pools is that they are owned by hedge funds and they either duped or bribed a famous author to write about them.
[edit] The comment below correctly points out my insinuation about bribery and Michael Lewis is unfair and snarky. I will point out that Michael Lewis wrote a glowing book about Jim Clark a decade ago, who happens to be an investor in IEX, so there is at least the potential for intentional bias.
IEX is currently not an exchange. What they offer is a dark pool connected in series with a Smart Order Router. That's what all the big brokers (e.g., JPMorgan, Morgan Stanley, Goldman, Deutsche Bank, etc.) have been offering to their customers for years and their dark pools usually offer a lot more liquidity. The big brokers have become better and better and smart order router technology to protect their customers as much as possible from HFTs. IEX is at least 5 years late to the party.
Perhaps they are planning on becoming an exchange one day, but I am not sure how they can do that while slowing down order executions. It seems to me that that would be a serious violation of Regulation NMS.