it blocks the addition of new *non-data* segwit transactions, which is teh only way to make a p2spkh without a hard fork
i think if people can make a new transaction type that wins enough support from users to pay the miners to mine it, that's the one thing about segwit that i agree with. i also think that the fee rate minimum on witness data should be flat, no special tier for witness data. that one thing alone would cut a shitload of the spam volume by itself because they wouldn't get any benefit over using op_return