From the point of view of old clients, segwit adds one coinbase output that contains the root hash of the Merkle tree that commits to the witness transaction ids. It uses 47 extra bytes per block, so technically, yes, it "wastes precious blockchain space". The blockchain on-disk can be pruned though (implemented as an experimental feature in Bitcoin Core 0.11, and with nearly full functionality in 0.12), so calling it "permanently" is not very accurate.
pieter keep up the great work! we're on your side.
don't worry about the lies, manipulation and misinformation, we're on it. we got it covered.
jl777 joined the dark side, and for all intents and purposes should be considered a troll with agenda.
don't feed the trolls