Regarding the disapproval, I think we have to be mindful as to who is doing the disapproving.
As a general rule, I suspect that most disapproval comes from older generations to those who are younger. But, I think this stems from the fact that life genuinely was different for them as parents.
Both my parents, and my in-laws (circa 80) were able to buy a house young, on the wage of one parent. Both mums didn't need to work so spent the majority of our formative years at home with is while the dads worked. My mum eventually went back to work when I was about 9/10, starting as a dinner lady at my school before taking on more hours to work in the school office too. My parents bought their 4 bed detached house for £100k in 1986 on my dad's salary of 3+1. They still live in it nearly 40 years later. They retired nearly 20 years ago.
So, they look at us now and they judge us for not doing it like they did. They might read in the paper that house prices have gone up, along with everything else, but they don't really understanding that, to buy a 4 bed detached house where we live, would cost us £600k+. Which is waaaaaay more than 4 x mine and my DH's salaries combined.
They know I work, and they know I love my job, but they don't really understand that I also have to work. Because it's just so different from their paradigm. They focus on how it's sad for the kids, without really understanding how different our kids' lives would be if we had to exist on one wage. And my god do I respect anyone trying to hold it together on one salary because they have to.
So, I don't think they necessarily intend to make us feel bad, it's more a case of looking at things from an uninformed or inexperienced perspective. When you add that on to the fact that life generally has changed. I couldn't have sat watching TV all evening, like mine would choose to, we had kids TV that finished at 5.30 with the closing credits of blue peter. We only got a 5th TV channel when I was 18. We had to do something else with our time. We didn't have our first computer until I was 18 and going to university. Sharing the landline with dial-up internet. I didn't have my first mobile phone until I was 21. Our kids can't really imagine what it was like growing up entirely analogue. Our parents couldn't bring us up like we have done our children and vice versa. Can I honestly say I would have been the same swat-of-a-kid if I had access to Nintendos, IPads, freeview/sky/netflix etc? That's not a fair one to answer because you can't change the version of life you lived through.
But, we add our own guilt for not being able to raise our kids the same way as we were. It's not a bad thing, it's just different. I suspect, our kids won't share the same guilt as we do when they have their kids... They will still have parental guilt but probably not for the same reasons.