If everyone had 11f mids across the board i would be okay with this. The problem is, some character mids are just way too slow, and D1s are 6f startup and most of the time -6 to -7 on block, adding this to the fact that the Block/unblocking game in MKX is also a mechanic, which won't allow you to use a normal on the first available frame they're negative, you end having people mashing for trades.
He poked you with a 6f move that is -6, the time you perfectly release block he is at -5, the instant you perfectly input your 15f mid, you will lose the advantage in the next 5 frames so your attack will reach on the next 10f, he inputs d1 again which is 6f startup, and you lose the trade again.
Mechanically the advantage was never yours to begin with, specially if 15f is your fastest mid or overhead or low, you're just doomed, having standing highs beating at least d1s during the time standing highs could win a trade, it would solucionate most of the low profiling d1s against better rewards considering they're 8 to 12f but hits high, people would still beat them by inputing d3s and d4, but those are far more negative if blocked in most characters.
