There would not be any "on the day" tickets sold for a game where the ground was closed to supporters. Season ticket holders would have already paid for a seat.
Paying by credit card or instalments to a finance agreement means that the season ticket has been purchased by borrowing the total amount due from a third party in order to pay the club. It does not equate to paying on the day. The club will have been paid, in advance, in full.
This is not "creating a them and us scenario" it is differentiating between someone who has entered into a contract with the club to gain access to multiple games by advance payment for a designated seat and someone who wishes to purchase, on an ad hoc basis, game by game, a seat. That does in no way diminish their enthusiasm to support the club, it merely demonstrates that one has purchased in advance and the other has not. The one has placed their faith in there being a match to which they will gain access, the other has decided to attend when it is physically possible.
Nobody is advocating a denial of income, merely a realistic way of dealing with the possibility that season ticket holders will not be able to attend games despite having paid in advance.
Apologies if this comes across as condescending but, I cannot really understand how anything I posted could be misunderstood?