The stereotype rarely looks beyond Liverpool, Manchester, Burnley etc. in the same way the North Western stereotype of the South and South east rarely goes beyond Kent and the Surrey commuter belt.
Well, maybe, but I'm very open minded about places. The South West and South East mean two very different things - generally, people in "the North" are more positive about the former of the two.
Liverpool and Manchester might not be everyone's cup of tea, the city centres of Manchester and Liverpool are unrecognisably modern and smart nowadays. They both have their fair share of good and bad areas, just like London has (and the 'bad' areas are very grim and 'good' areas are often completely unaffordable for SE England average earners). That's one reason (there are others, of course) why so many are forced to "commute in" to London and do not choose to live there.
To be honest, Pacers aside, the rolling stock you have isn't really that bad - there's no reason why 150s, 156s and 158s need to be dreadful inside, a good refurbishment (not just changing the seat moquette) and decent maintenance regime would solve some of these problems.
Yeah, well the problem is Northern has 91 Pacers, hence why so many (often inappropriate) services have to be operated by them. The fleet on the North West side of Northern mostly retains bus seats and "Merseytravel" refurbishments (which have rock hard 'seats').
All the rest can be sorted out. 150s aren't bad, some of the "refurbishments" they were given by the likes of First North Western have made them cramped and unpleasant. 153s and 155s aren't bad either, they could be brought up to a better standard. 156s and 158s, even without a major refurbishment, are luxurious by our standards, 333s are fantastic! 150s, 153s, 155s, 156s and 321s could be great trains with a SWT-style makeover...
Even so, you take out the Pacers and services collapse. It all stems from the ridiculous notion of the Northern franchise being "zero-growth". It's been nothing of the sort, with figures rising yearly. Many object to LM getting preferential treatment over Northern when it comes to stock. The pacer problem is effectively being ignored, while even more cast-offs head Northern's way (still waiting). FGW's 142s are going to replace the 3 temporary 180s.
I know the 319s (or more 323s from LM) are supposedly coming after the Lancashire electrification programme is complete. They are cast-offs too, albeit much welcomed. I hope they have a decent refurbishment.