Given that these are the largest groups of migrants in Ireland
Drinking or not, the Irish hate them and set hotels on fire to express their dissatisfaction. Quoting from irishcentral.com:
Ireland has a huge housing shortage, we have over 10,000 people living in one room in hostels or hotels, with no washing or cooking facilities. This is not right that Irish children are living in these with hundreds of migrants also. We have Irish people sleeping in doorways on our streets. Yet any empty houses are given mostly to migrants. If it goes on like this Irish people will call for an Irexit.
they wreck the existing ecosystem of pubs.
An ecosystem where people get drunk and act like idiots?