Why aren't HMLs allowing seller's equity as down payment?

[Rodney Dixon]

I'm currently working on a income producing quadplex deal in Tampa, FL in which I've convinced the seller to carryback 40% of the purchase price. I contacted 2 guys who lend hard money in my market whom through past discussions have stated that they lend up to 70% of the purchase price. When I ran the deal by them and how I was mapping to pull it ofl w/the hm 1st for 70%, have the seller sign a contract to carryback 40% and the difference between the 60% in hard money funds that the seller was actually going to receive and the 70% that the hml was actually funding, I was going to pay all the deal costs(closing fees, points, etc..). 

However, neither guy didn't want to do the deal insisting that I need "skin" in the game. 

So now I'm seeking insight as to why HMLs refuse to allow these creatively structured deals to be deployed?