Not sure if you're a fellow Brit or not. Either way, I think most British people are quite content in the security of their community. Most communities, even in large cities, harbour a very small population of Muslims in comparison to the general population. With the exception of certain parts of London, Luton, Bradford and other northern towns. And even in those communities the amount that venture into radicalisation is very small. I think overall the UK has an incredibly tolerant, inclusive community - especially in comparison to our neighbours on the continent where ethnic minorities seem to be largely confined to suburban ghettos. The generally cohesive nature of Britain's relationship with it's Islamic population is most evident immediately following terrorist attacks. Muslims standing together with banners denouncing IS with slogans like 'ISIS is NOT ISLAM'. The Islamic extremists which have wreaked havoc on our streets are a phenominally minute fraction of the overall Islam community.
The Union Jack is a symbol of all that we stand for as a free democratic nation, which encourages freedom of speech from all corners of society, with no ethnicity or religion marginalised. That's what it has come to stand for, which in my opinion is a lot more meaningful than a bit of cloth with a random pattern that we're indoctrinated to follow without question, as it has been in the past.