I thought that testnet coins have no real value (or at least nothing compared to the main network), how come do they accept them as a payment method? LN is still in Alpha at the moment so I doubt people will start using it, until everything is stable and running smoothly.
There are even people giving away loads of free testnet coins for use on them, so they basically are worthless. I don't think they would be making any profit from accepting LN coins so I guess that's a dumb/honourable decision of theirs.