There's several things worth noting about those articles Tei.
First off the date stamp. It took over a week for the Guardian and BBC to even admit anything had happened - the German papers (Frankfurter Allgemeine etc) and US papers (I happened to have a Wash Po sub at the time) were reporting it within 2 or 3 days. There was a distinct feeling (there were multiple threads on this at the time) that the Guardian and BBC were deliberately holding back from reporting (as they did with Rotherham, etc.) because they didn't want to report anything that might fuel anti-immigrant sentiment. Now this of course is important, and the second of the links you give importantly puts it in context by reporting a lot of Arab immigrants to Cologne saying "not in my name." But complete censorship of news this major - which went on for the best part of a week - is not acceptable.
Second the number of victims. At the time of the attacks, the German penal code only categorised an attack as sexual assault if a woman could show she physically fought back. Freezing with terror, or being unable to move because of the press of the crowd meant no "official sexual assault" took place. This meant that official figures for the number of victims was way below the number actually assaulted - and the Graun and BBC stuck rigidly to an editorial line of "only the official figures can be reported" while other (mainstream and respectable media outlets both in Germany and the US) were noting that the actual number of victims was far higher.
Finally there's Hinscliffe's victim blaming and minimising - "it was just mugging for mobile phones" (she wasn't the only person doing this - Jess Phillips in what I hope was a rare lapse said roughly "worse things happen on Birmingham New Street station every weekend). Whereas in fact the two scary things were (1) it appeared to be an organised "flash mob" planned in advance via social media and (2) there was some circumstantial evidence to suggest it was a form of taharrush gamea, a form of organised sexual violence used for instance in Tahir Square in Egypt in 2005 with precisely the intention of making the public sphere (and in the case of Tahir Square, political engagement) off limits to women. (There are a number of organisations within Egypt and nearby countries campaigning against this phenomenon). Now it might have been, it might not have been, but it was worth reporting on in a nuanced way, not dismissing the whole event as "well, if they will flaunt their mobile phones."
Now it was always going to be an incredibly hard event to report decently. "They" (unspecified other) are raping "our" women is one of the oldest and most pernicious forms of propaganda (lent credence by the fact that it's so plausible, because rape within war is pretty much universal - the "bad guys" do it, the "good guys" do it, all races, colours and creeds get in on the act). So it was difficult to find the right editorial line which captured the facts, put it in a wider context, explained why it appeared to be a new and scary phenomenon and not just "New Street on a Saturday night". But the distinct feeling I and a lot of women got watching this horror unfold in real time is that the BBC and Guardian didn't want to report it at all because it didn't match their general editorial line.