I suspect that a good portion of people involved in BTC are either HODL's or traders. I don't see why a HODLer would think it is a good idea to wrap up much funds in LN, since it involves keeping funds in a hot wallet. Also, I am not aware of any major exchanges coming on board. If a few of them do, I can see lightning as an excellent way to arb. However, I think coming up with an easy way to handle the channels may be a challenge for a major exchange at this time.