The intention is not to staff the new gate "from 6am to midnight" - and never was - and we shouldn't realistically expect TfL to do so.
This is "a remote self-contained ticket gate" which is designed to be operated at times without the need for a ticket inspector standing by the gate. I understand from Southern that they intend to place a person by the gate during peak use - during the morning and evening rush hours. But at other times, the barriers will be opened automatically by passengers with tickets and Oystercards. Remote gates such as these (with a CCTV and buzzer system to help those with problems) operate successfully in many suburban stations already and their operation will be made much easier when Oystercards become the norm.
I'm unsure what you mean Gingernuts about the issue being the "location of the gates etc". Surely, the gates are going to be placed close to the existing bollards on Perry Vale where there is easily enough space for passengers to collect safely at the foot of the stairs.
Step-free access via the Perry Hill car park is, of course, an idea which would be welcomed by all passengers but this will only be achieved in the medium to long term. In the meantime, all passengers want the choice of entering and leaving the station via the steps - so let's allow them this choice. If the way to achieve this is by erecting gates (and both Southern and TfL simply won't budge on this point) then let's proceed. Why should this be a worry?
The alternative is to see the gates locked up for part or all of the day again. Who wants that?