They probably discontinued use because the only practical way to clean a Ithaca 37 requires taking stock off. The fire controls slide out back as well as bolt group when disengaged from slide arm. I’ve never taken a 87 apart.
I only sold 3 of them, the 37 cult didn’t like them. The Rem 870 and Moss 500 aren’t near the gun but are much easier to strip to clean.