But people are saying they don't check on board now, so why will they start when the gates are in.
Well, if there aren't gates now, why are they already not bothering to check? That's a separate problem, and I wonder if that is company policy or staff are simply not checking?
I accept that gates aren't quite as important for Intercity trains, but they do still serve a purpose - and it's not just Intercity services going from King's Cross (and FCC do use platforms other than 9-11).
EC does of course really need gates at
all of its stations (including York!) and after that, the on-train checks are really needed only for things like people upgrading to First Class. That annoys me too, but not as much as someone not paying at all. But, they're not all going to get gates - just as the small stations won't get them either.
We talk about KGX as if no other major terminus has gates, when many do. Do they cope? Do they get so busy the gates are all opened? I've not really seen that at Liverpool Street or Waterloo, so I am guessing that with more gates (and KGX has quite a few so far, with many more to come) they won't need to be opened as they are at, say, Welwyn Garden City where there are three normal gates and one wide gate - to manage people in both directions.
A totally ridiculous situation, which either causes dangerous queues back to the platform edges - or has them opened. I'd say it's pretty likely you would know exactly what trains will ensure being let through every single time due to the number of people alighting at the same time.