Can't agree. Sikhs and jews definitely do things that stand out from the crowd. I don't think that explains why muslims get focused on in particular.
Some Sikhs and Jews do stand out from the crowd but most don't. Many Sikhs don't wear a turban or have a beard - in some Asian communities it is all but impossible to spot a second or third generation Sikh by appearance alone. You see a heck of a lot more karas (iron bangle) than turbans or beards and these are often tucked up a sleeve. For many Sikhs losing the turban and beard was one of the first things they did upon arrival in Britain.
And how do non-orthodox Jews stand out from the crowd? There are many, many thousands around the UK who are utterly invisible virtually all of the time.
But Muslims? There is a definite increase in the wearing of identifiably Islamic clothing - hijabs, taqiyahs, etc. The fastest growing segment is unquestionably amongst the young. It is becoming routine to encounter Muslim families where the parents shun Islamic dress, and have done so for decades, but some of their kids insist upon it. My partner grew up in a mixed Hindu/Muslim area and is constantly amazed at how it has changed in the last 15 years. At school in the eighties nobody
was wearing any of this stuff - all of the Muslim kids dressed exactly the same as the Hindu kids (girls with a plait, boys in a jumper knitted by Aunty). Not a single head covering in sight, male nor female, except on some awkward Sikh boys tormented over their topknots. Some of those kids now wear Islamic dress but their young cousins and relatives wear it much more. In areas where the Muslim population has remained essentially unchanged since the 1970's there have been real changes, mostly in the last 10 years. There aren't that many more Muslims - it's that some of the existing ones are dressing very differently in some cases and suddenly became much more visible. I guess it's on obvious response to feeling that your identity is under attack, to defiantly declare it?
On a personal note I especially enjoy the absurdity of white converts to Islam pottering around Tesco dressed for the desert.