Mr Mitchell was speaking at Mayfield and Five Ashes Parish Council's annual parish assembly held at Five Ashes village hall on Monday night.
While explaining why cuts were 'economically necessary' he also held out hope to residents saying an additional half-hourly service would be re-introduced at peak times.
The chief executive explained how he had left the rail industry to work with buses which, he felt, better served the transport needs of communities suffering the greatest deprivation. But he noted the bus industry had been in 'terminal decline' with bosses raising fares again and again as numbers of passengers reduced.
The body blow came, he said, with Covid. "We never had a chance." But he was determined to reset this company's viability after redundancies and other cutbacks saved the company £1.5m. He also introduced a five year plan.
Stagecoach overall had borrowed £1b which was being paid back at 7%. This was coupled with the need to decarbonise and schedule introduction of a new, electric fleet. He noted that to succeed, buses must offer a better alternative than getting the car out, offering regularity, reliability and a more comfortable method of getting from A to B. He also quoted the most effective and well-resourced bus services in the UK were based in Edinburgh, Brighton and London where timetables were hardly needed as 'there is a bus along every few minutes.'
He was questioned over the service's unreliability where passengers were left waiting in the cold, sometimes for two hours. He said the 51's problems arose from unpredictable roadworks, particularly in Eastbourne which suddenly popped up and made accurate scheduling impossible. They also occurred along the route in Hailsham and Heathfield. He also cited the county's potholed roads which affected ticket machines and made the service app even more unreliable.
The 51 bus, he said, was viable from Eastbourne to Hailsham, OK from Hailsham to Heathfield but from Heathfield to Tunbridge Wells it clocked one passenger per mile travelled, with a net loss of £1.2m. The service costs £1.7m to operate.
He said: "To continue we had to strip the resource out and drop from a service every 30 minutes to one every hour." And he emphasised the need for financial support from county councils "on top of all the other things they have to pay for like adult social care."
To comments from the floor reporting how families had to use the car to ferry children to important exams as buses did not turn up, he said he understood the predicament as he had children of his own needing to travel to schools in Ashford and had to drive them there.
But he held out a glimmer of hope saying better management and improved savings meant a peak-time half-hourly service could be re-introduced this autumn.
Mr Mitchell was praised for being brave enough to face his critics, many of whom were elderly and had no other means of transport.