Not everyone is reluctant to discuss the New Year assaults.
Those lovingly referred to as "right-wing racists" have been discussing the issue passionately.
However, it is true that many people are reluctant to discuss them. This is especially notable given that they are often very vocal about women's rights and sexual assault. For simplicity I shall just call them "the left wing".
Take it from the horse's mouth:
the attackers are widely described as looking Arab or north African. Which is why, of course, liberals like me are reluctant to talk about it.
(Let’s not shy away from asking hard questions about the Cologne attacks | Gaby Hinsliff )
In other words, the left wing is afraid of being labelled racist, Islamophobic etc. They are also afraid of stigmatising or blaming immigrants from poorer and/or wartorn countries, especially since it is a minority that is responsible for these acts, and especially because they are mostly Muslim.
This fear of criticising "minorities" is not a new phenomenon.
England's Independent Inquiry into Child Sexual Exploitation in Rotherham (1997 – 2013) (Independent Inquiry into Child Sexual Exploitation in Rotherham (1997 - 2013)) noted that,
By far the majority of perpetrators were described as 'Asian' by victims, yet throughout the entire period, councillors did not engage directly with the Pakistani-heritage community to discuss how best they could jointly address the issue. Some councillors seemed to think it was a one-off problem, which they hoped would go away. Several staff described their nervousness about identifying the ethnic origins of perpetrators for fear of being thought racist; others remembered clear direction from their managers not to do so.
Similar concerns probably prompted Cologne's ('Cover-up' over Cologne sex assaults blamed on migration sensitivities) and Sweden's attempts to cover up their sexual assaults (Swedish Police, Accused of Cover-Up, Look Into Reports of Sex Assault at Festival).
One left-wing response to Cologne's New Year assaults is to claim that men from all cultures sexually assault women, and that the problem lies with men - not just immigrant men (Rape Culture in Germany Is Not an Imported Phenomenon | VICE | United Kingdom).
Yet, it is notable that past New Year's Eves in Germany did not see similar outbreaks of sexual violence.
Even more notably, take for example statistics from before Munich's 178th Oktoberfest in 2011 which reveal that "Each year, about 12 women attending the Oktoberfest report rape or attempted rape". Given that Oktoberfest lasts for 16 days, this is much less than the Cologne (Armbands Against Assault at Oktoberfest?)
And during 2013's Oktoberfest, in 11 days there were 12 reported cases of sexual assault (Sexual assaults double at Munich's Oktoberfest Sexual assaults double at Munich's Oktoberfest)
These numbers compare favorably with Cologne's 381 sexual offences (including 3 rapes) (Cologne attacks: first arrest over New Year's Eve sex assaults). All these happened in just a few hours, whereas Oktoberfest is a morning to night event over 16 days (Oktoberfest 2016 - Program » Oktoberfest.net).
Clearly the Cologne sexual assaults were of a different order of magnitude from Oktoberfest Business as Usual so there is something very disingenuous with this claim that it is a problem with men - not just men from certain cultures.
One can see that in Egypt, one study found that 99.3% of Egyptian Women and Girls report that they have been sexually harassed (99.3% of Egyptian Women, Girls Have Been Sexually Harassed). Another found that 62% of Egyptian men reported that they had sexually harassed women (Two-thirds of Egyptian men harass women?). By comparison, in the UK only 23% of women reported experiencing sexual harassment in the last 5 years (Facts and statistics on gender inequality).
Just because you take people from one country and put them in another doesn't mean that they are going to behave differently.
Probably the saddest part of this whole story is that the chief victims of migrant harassment are assuredly the immigrant women who are living with them, who are not as able to have recourse as other women in these European countries (German authorities accused of playing down refugee shelter sex crime reports).