Maybe it’s not so much about the album being considered bad, maybe it’s more about the band having not-very-pleasant memories of the time it was recorded. From an
interview with Phil Chevron:
„The band was going through a very volatile period at the time. People were having domestic issues and other things were happening to people and people's families. Daryl and I witnessed The Hillsborough Disaster, there was a hundred issues feeding in. A lot of things came into the blend that made things very difficult, and off course Shane started taking a lot of acid at that time, which is no great secret. That changed things because we constantly had to work around his state of mind. So for the next album (Peace And Love) we said lets 'publish and be dammed' - we were unhappy so lets tell people we were. It was the same token with 'Hells Ditch', there is a more relaxed air about it. There is a more pastoral and country theme about it. Shane had been to Thailand trying to sort himself out. We recorded the album literally in the country in Wales. We stayed together miles away from anybody. So there is a pastoral theme, almost like that Sixties Hippy thing - getting your head together in the country. The whole album was like trying to find the light again. It is called Hell's Ditch because that is kind of where we were jammed into and we were looking to the 'Sunnyside Of The Street'.“
As for the opinions of the listeners – maybe some don’t like the different sound of the album (Shane: „On Hell’s Ditch I couldn’t write any Irish stuff. I just wasn’t in the mood, and they wanted an album, you know. So I wrote some rock. And you know I don’t like straight rock, so I put some Spanish influences in it. 'Summer In Siam' and stuff like that.“) But browsing this forum, I think it has quite a lot of fans. And I agree that it’s amazing.

Eagles may soar, but weasels don't get sucked into jet engines.