There are always people late at football matches, because you see the empty seats gradually filling (and at the start of the second half too). Although, to be fair, a couple of Prem matches were delayed this season because of problems on the roads, which prevented access to the stadium. Plus, speedway is nothing to do with football - or any other sport.
It's British speedway tradition for the parade to be part of the meeting, i.e. Ipswich speedway has always advertised the start time as the time of the parade, i.e. 7:30pm and first race at 7:45pm. I really don't see what the problem is - in the list of British speedway's problems, this must be rate in the bottom half a percent.