The question is why they weren't able to beam Spock out of the volcano.
nuScotty reprogrammed a shuttle's transporter for transwarp beaming, and he probably used it to beam nuKirk and nuSpock aboard the Narada, yet he DIDN'T keep the algorithm in the Enterprise's transporter systems?
But who am I to look for logic in a script where a space ship hides under water for no reason and cannot withstand the heat of a volcanic eruption, which is minimal compared to what a ship like the Enterprise would need to endure when it, for example, enters the atmosphere of a planet to hide under water.
Its been pointed out that it wouldn't have trouble with heat but ejecta is a different story. So they got one word wrong.
They also changed hypernova to supernova in ST09 so as to not confuse audiences, though hypernovas still wouldn't destroy the universe...
Perhaps like ST:Enterprise, transwarp beaming is too dodgy in it's early stages to adopt. Maybe a few decades hence that wouldn't be the case, but it still is here. Remember Scotty lost a certain prized beagle, so how often has it been successful up till then?