There is good evidence to indicate that the IRA Army Council is still heavily involved in running Sinn Fein. And it is no wonder, because the links between the two organisations are pretty tight and always have been. The party still calls itself "the political wing of the Provisional IRA". In response to an audience member shouting "Up the 'RA", Gerry Adams famously replied with glee "They haven't gone away you know".
Sinn Fein to this day praises and commemorates former IRA murderers. Michelle O'Neill comes from a family of proud IRA members. I could go on.
Endorsing the organisation now is endorsing its history and aims, which haven't diverged despite the young faces and heavy layers of PR gloss.
> pride at having held off the British Army
And a lot of civilians who guarded prisons, happened to be going to work, were 'suspected' touts, were buying fish and chips, or were watching military parades to commemorate real sacrifice like that made in WWII.
Real reconciliation would be possible with moderate nationalists, not people who call Unionists "bastards" in private, or say "equality is a trojan horse for Nationalism".