I'll not pretend to be an expert but it does look like a deliberate delay...the checks required would not even take 6 months let alone 2 years...I need to see the average processing time to make a firm conclusion.
heres an interesting stories from people i worked with about their experiences with Irish naturalization
one came in '94 applied in early naughties and got it in under 2 years
another came in '96, applied in '06 (thats 10 years in the state continuously living and working and paying taxes from about the time when people were still leaving the state), still waiting last i checked this person has excellent English with native accent, goes out on town like us irish, pays taxes, is of good character and is educated up to masters level . how can it take over 3 years to make a decision on that case and run background checks?
one has to wonder as in the uk the process is a couple of months ....