I've played online with both PC and console, and the input lag issue with online play on console is almost certainly a server issue.
I'm on a wired connection for both devices with 500 Mb/s internet speed. For games on PC, I always have ping times between 10 to 15 ms.
When in "play now" online on PC, it's actually a good experience. Input lag is only ever noticeable with jump shot releases, and even then, it's only very slight. You can easily adjust to playing with it because the server response is consistent (the degree of input lag isn't fluctuating all the time the way it does on console). In those experiences, 2k's servers seem fine. The only problem is that the player base for NBA 2k very heavily skews toward console. Once you advance past the third tier ranking in "play now" online, the matchmaking pool gets very thin. Sometimes you wait 15 minutes; other times you just can't find a game.
When in "play now" online on console, the input lag impacts the whole experience. It's noticeable when trying to perform most actions, and the degree of responsiveness is always fluctuating, so trying to adjust to it isn't really an option either. It's a pretty poor gaming experience, especially when knowing that better results are achievable on PC. While I understand that the hardware specs of consoles often aren't up to par with PC's, it's impossible for the difference in performance to be attributable to that alone. Other games don't have a comparable difference in performance dropoffs when it comes to online multiplayer.