The answer is simple: $$$
The online streaming you are referring to is part of "TV Everywhere" and most of them won't renegotiate their deals with Directv just for this, it's only done when the entire contract needs to be renewed. Since Disney and DirecTV are now in talks to renew their contract, Disney's Watch services will be included, but you know what this also means, our bill is going to go up because Disney is going to want a higher fee for ESPN.
Same goes for FOX Sports 1.. this channel was originally SPEED, which had no live streaming, and, industry sources say it is under the original SPEED carriage deal with DIRECTV, and depending on how long that contract is for, we could be waiting a while. You'll notice all other FOX properties(except broadcast) with online streaming have Directv as a provider. Also, Comcast and FOX just renewed their deal in 2/2013(FS1 was launched in Aug2013)... again when this is renewed our bill will go up again.. SPEED cost 23 cents per sub, FS1 is supposed to fetch 80-1.50 per sub... YAY!?!