Plenty simply stopped attending Hull City games. Of course we had, and still have, those who used to catch the buses on a Saturday morning outside YEB to watch Leeds and Man U, although they don't board outside YEB anymore for obvious reasons. Some days there was one bus chugging down the M62 to a City away game and we would be passed by three or four coaches full of Hull people going to the other two.
But the biggest draw on our attendances from 72 to the mid 80's was local rugby league, which peaked in 1980 with the all Hull RL Cup Final.
City as a club did little to keep the support we gained from 65 to 72 ish. Virtually no investment at all in the team and we sold every player who topped our goal scoring lists, one by one, season after season. We slipped further and further down the football league ladder and no-one seemed bothered. As we shrunk as a club both Hull RL clubs welcomed our disillusioned supporters, and it must be said that everything we didn't have as a lower league football club could be got at the rugby. Silverware, the reflected glory, beer in the grounds, no segregation, cheaper, no police or heavy handed stewarding, television coverage and a council and local media fawning over them. RL was fashionable in Hull at the time and we suffered as a result.
Also Boothferry Park suffered from a lack of investment and when the rest of football were redeveloping their grounds we did the bare minimum and sometimes not even that.
The capacity at BP was cut so drastically that we couldn't get more then 10,500 in the ground if we wanted too.