To be expected.
Is it?
A bit of a clichéd remark from one of those sanctimonious rugby fans (to adopt another cliché) towards those thuggish football fans. Football has done a pretty decent job of keeping this kind of behaviour in check in the past 20-30 years since the very grim days of the 1970s and 80s. For whatever reason, this kind of behaviour does seem to be creeping back in, and clubs appear pretty quick to respond and ban the small minority before it grows any bigger.
This sort of conduct is not "to be expected", it is to be condemned and eradicated ASAP. I hope CCFC succeed in identifying those responsible and banning them from future games as they have no place in any sport.
No sector of society is without its mindless morons, and I have occasionally had to remind rugby supporters sitting near me how to behave. I'm not talking about people giving rugby a go for the first time and struggling with previously inconceivable mix of availability of alcohol and lack of supporter segregation; these are Wasps fans, wearing Wasps colours, who should know better, but may have over indulged and over stepped the mark of what most of us consider to be acceptable. Believe it or not, the overwhelming majority of football fans have similar expectations of acceptable behaviour, and it is not their fault that football will forever attract that mindless minority who see it as a vehicle for their thuggish instincts. Hackneyed snobbery dismissing it as "to be expected" isn't particularly constructive.