They are accepting it, and have been for a few days. They accept bitcoin and monero, too.
They will build the platform on bitcoin,with eth and xmr as alternatives, but many vendors will not accept them.
The problem faced is simply bitcoin and its confirmation time, which can be solved very easily.
BTC will reign unless something that is hard to predict occurs.
There are too many millions invested in it by parties that have power. Plus, BTC is the only cryptocurrency that people actively pursue ownership of.
Dabbling with ETH, is a way to increase the BTC you hold.
It's not that simple...
To decrease transaction time, you need to pay a higher fee to get priority over other transactions. The more valuable bitcoin becomes, the more expensive this fee will be.
The other problem is anonymity. Before sending your coins to the market you would need to, at the very least, tumble them using a tumbling service... Which again, isn't free. The service will cost you a small percent of your coins.
Transaction time, tumbling, combined with the time it takes for the market to credit your coins to your account makes the total wait time close to an hour or so. :/
This is the part where I shamelessly plug my favorite coin... XMR
You don't need to waste money to tumble it, as it has true anonymity built in so your transactions are completely secure and private. Transaction time is generally less than a minute, much faster than BTC, and it's got great devs supporting it... Although, it is true that not all vendors take XMR, but a large number already do and are reporting an increasing trend of transactions using the coin. If there were ever a coin designed specifically for the darknet, that would be it, IMO.