I think it is discriminatory. Not because you can't drink a football but becuase you can't drink at men's football, there are no restrictions at the women's game.
I'm a regular at men's football, and have been since the dark days of the 1980s.
Now, the absolute majority of fans are fine with or without a drink, but football attracts huge numbers week in week out and anywhere you get massive numbers and alcohol, you're going to get some problems, but the rules aren't based on attendance, they're based on sex and sport.
I attend football at a Premiership Club, a League 2 club and a National League Club. The NL are newly promoted and getting crowds of 1200 pw. There's never been any trouble there to my knowledge, but now they can't sell alcohol during the game, which was an important income stream for them.
There is trouble in pubs across the country every weekend. No one thinks all pubs should be prevented from selling alcohol, but those who have repeated issues lose their licence. Why is football treated differently?