While re-unification has romantic appeal to some Catholics in Northern Ireland, the suspension of Home Rule and the introduction of an army presence was initially welcomed as a protection against political Orangism. Even during the 'Troubles' it was more welcomed than perhaps many Catholics would care to admit (and always preferable to the police)
I wouldn't over-egg the pudding; the welcome wore out very quickly after the Falls curfew and the introduction of internment. It also depended on the regiment; a lot of Scottish regiments had a bad reputation for dealing with Catholic civilians and the UDR (officially part of the British Army) a worse one.
Yeah, the hallowed Black Watch got a very bad reputation with the Nationalist community. However, the UDR went even further and was effectively a wing of the UDA.
Several Irish posters here, as Observer states, also underestimate the desire for a united Republic. While it is certainly not a majority, on either side of the border, there is still a strong Republican constituency. Further, despite posts that label Sinn Fein a single issue, Adams party, the goal of an all Ireland party with a voice on all issues continues. There is a generational shift occurring with the likes of a Pearse Doherty leading. Ive also seen some posters say that no one was speaking out against the greed and corruption inherit in the Celtic Tiger era. I'd say you were listening to the wrong people or refused to listen to it because of some culture cringe. The media and government functionaries were not warning but others were.