En route to looking up something else, I chanced upon this Lebanese priest's insightful and helpful explanation of this phenomenon.
As we said, this is a common practice in Muslim countries. In fact, population growth, as well as a renewed religious fervor, has meant that the existing mosques and places of worship are not enough to contain all the faithful on Friday at noon. Given that this is the case in Muslim countries where the separation between state and religion is virtually nonexistent, the faithful have been in the habit of occupying sidewalks and streets near the mosques and of diverting traffic.
For over a decade, this practise has also developed in Europe, although it is perfectly illegal, since the street belongs to all pedestrians as well as motorists. This situation is recognized as totally unacceptable by all reasonable people, regardless of the principle of secularism. It becomes even more so, if one takes into account that these exceptions are no longer exceptional, since it takes place every Friday. And since this exception is applied to a specific religion, Islam, the impression of many is of an “invasion” of land, a kind of “conquest” of the national territory by the Muslims. There are no justifications for this occupation of public territory.
On the contrary, should a group of citizens (Muslims, Christians, or other religions) make an official request for an exceptional use of a public road for a limited time, for a party or ceremony, this would not pose a problem. It seems to me that the current situation does no more than reinforce and justify Islamophobic reactions. And this, in my opinion, is a fundamental point. It has become commonplace to speak, rightly and wrongly, of “Islamophobia.” Of course this may motivated by more or less racist reasons, which is totally unacceptable, even if it happens everywhere. However if people, in the name of the particular group to which they belong, behave in a manner contrary to the laws and rules of the land, or even to the traditions and customs, then, these people are responsible for the resulting negative responses. In this case, Muslims are partly to blame for the Islamophobia which is expanding throughout Europe. It is up to Muslims themselves to protest against those who cause these reactions and educate their co-religionists.