The mains two would be that in general the upper-middle class and wealthy don't understand the financial incentives of the poor. And the poor tend to believe everyone with a job earning more than £35,000 is "rich" and needs to be aggressively taxed.
For example, when I tell people that most of my family choose to have children in their early twenties as a means to move out of their parents homes those who are wealthier simply don't believe me. They simple don't understand that if you have no skills and your family have no money, you're not going to afford a house no matter how hard you work as a cleaner or cashier.
So this means that most people in my family who live in nice houses are actually unemployed, and typically single mothers. While those who work generally live with their parents or in small run down flats.
Further, it's very common for these people to be getting so much support from the government from various disability allowances, child support, and benefits such as support for energy bills, free school meals, disability cars, etc, that they actually can't get a job because doing so would dramatically reduce their standard of living. So for example I know a single mum with 5 kids who is a drug addict. A large part of the problem is that she has nothing going on in her life so she just sleeps all day and then does drugs in the evening. My girlfriend tried to help her get a job a few years back but the adviser told it wouldn't be financially sensible decision given how much she'd lose in benefits income and support. And well, now she's a prostitute because it's cash in hand and she recently been in hospital for liver failure... I could give you countless stories like this from my family.
But the point I'm trying to make is that if you're poor and working class you won't be able to ever afford a house in the UK. So instead you're basically forced into claiming benefits, and to improve your standard of living you need to learn how to exploit the system while doing illegal things on the side. The thing you're not incentivised to do is work.
On the other side of the coin my family believe myself and those social with are "posh", because we earn say £50,000 - £100,000 and most of us can just about afford a 2-3 bed home by 30. I know a women who was impressed by a guy she was dating recently because he had a £38k income and was a manager in a retail store. I mean, that's not a bad income, but if you're middle class you would never consider that wealthy...
I'm pretty lucky because despite going to crappy schools I was autistic enough to be good at computer stuff which allowed me to break the cycle. But even I'm in no position to afford children right now. And realistically me and my girlfriend only have 5 or so years to get our finances in order if we want to have them. So in all likelihood I will never be in a position to afford children and I have above average income.
The truth is a household income of around £60,000 in the UK won't go that far after tax and expenses if you're living in a major city. You might get to a good place eventually, but you'll never afford a family before you turn 30. You might afford it by maybe 35-40, but this assumes you make a lot of good decisions (or have wealthy parents).
So I get quite upset when my family tell me I'm wealthy because I envy their lives so much. I want children like them yet I know that I'll probably never have them. Instead I work long hours and I'm worrying constantly about budgeting. So given what I see, when I hear cries to raise taxes on people like myself to give even more to people on benefits it pisses me off a little.
My controversial take on this is that we should not be giving pensioners non means tested benefits. The majority of our tax goes to free health care, state pensions and various other state benefits for wealthy elderly retirees. And almost none of this support is means tested. Instead we should be encouraging retirees to sell their homes and pay for their own retirements and care. This would take tax burden away from the young while increasing the supply of houses for people to start their own families. It would also be a fairer system because less people would inherit wealth from the elderly, and instead it would encourage building it. I think we should also consider a lower tax rate for people in their 20-30s and for working parents. This will allow the young to build wealth to get a good start and support families on their own.
Obviously, in an ideal world there would be enough money for everyone, but there isn't. Therefore it makes little sense that most tax revenue gets redistributed to wealthy retirees at the cost of the young and poorest in society. We probably also need to look at improving the incentive structure of the benefits system. Generally I'm fine with the benefits people receive today, but we could probably do a better job at ensuring people don't feel like it's ever a bad financial decision to get a job or earn more because they'll be worse off. My guess is that this will also reduce crime, because again, part of the reason people in my family sell drugs or get involve in prostitution is because of how benefits are means tested.
Of course, none of this is politically feasible given voting demographics and what seems to a popular opinion in the UK that the solution to our problems is even higher taxes and even more benefits... And perhaps I have the wrong solutions, but I'm sure as hell that the solution isn't raising taxes and giving retirees better health care, larger pensions, more support for energy bills, etc.