While he's right, I imagine VCs get such an unbelievable volume of cold e-mail that sorting through it is really time consuming to the point of impossibility.
Why not create a smart form, YC style, that take some time to fill and provide the most important data about a startup for them in an easy to read format?
A simple "submit your AngelList page" might go a long way.
We had this problem for a long time. We had a generic cold inbound form and got such an abundance of email with no good way of filtering it that we just gave up on it. However we realized that with a bit of focus we could turn this into a good way to get some great deals we would have otherwise missed.
We now again have an founder application form (https://fundersclub.com/founders/apply/). It asks some generic questions followed by more specific metrics based questions depending on what type of company you are (Consumer, B2B etc.). We can then filter based on these to surface what we believe to be good opportunities to the top. Would love any feedback on the metrics we ask for - we try to keep them as data focused as possible, as once you start asking more qualitative questions you go right back to being overwhelmed.
I'm just curious - why don't you delegate the cold pile to junior staff and make them do brief (39 min) writeups of incoming proposals? Film production firms (my field) are like VCs in that they receive many awful proposals and only a few of the good ones will actually work out, but they employ people to read incoming scripts and work up short summaries to indicate which ones might be worth their personal attention.
"Social proof" is important to VCs. I don't blame them for not sifting through cold emails. If you're worth investing in, other people should already be talking about you.