Guilt might not be the right word. Maybe responsibility.
I think it is incorrect to think we should just ignore responsibility for past actions as a society (especially recent) using the guise of "that past is the past" or "I didn't do that so why should I care".
We know our society had some forms of discrimination and social biases against groups/minorities. I don't think it's a bad trait of society to try and correct some of those injustices. Do we go overboard sometimes? Absolutely. The pendulum often swings a bit too far. I mean, I think some of the handicap rules are just a huge waste of money. Being in construction, I have seen the ADA standards for sidewalk handicap ramps change numerous times in the past 2 decades and governments spend millions of dollars going around and changing out perfectly fine concrete ramps and replace them with completely overkill designs that cost way too much money.
Another example in construction is the recent changes to sediment and erosion control, which can add $10,000 easy to every house built (people don't even realize they're spending it on this). And the problem is it would cost $1000.00 a house to prevent 90% of sediment/erosion loss but the Natural Resource fools are obsessed with it so much they spend 90% of the money chasing the last 10% of effectiveness (and meanwhile farms are completely exempt from sediment and erosion controls). Remember we are talking about TEMPORARY construction expenses. We put all this money into jobs just to tear it all out at the end.
Those are just two examples of how the system works incorrectly. I'm all for spending that first 10% to 50% of money on a "cause" of restitution for past inaction in some degree. But there are always those that want to take advantage of the system and push the cost way, way up looking to correct every last nook and cranny of the problem, even those when the cost benefit analysis is ludicrously unbalanced and wasteful.
That's why some social injustice issues I have no problem with. Giving gays the right to marry? Who the **** cares. That doesn't cost us anything. Reasonable social welfare that can help the most common 90% of problems? I'll listen. Making social programs that cost 50% of the money trying to help the last 10% of problems? No way. We can't protect everyone from themselves. Sometimes we have to acknowledge that not all people can be saved. Give people reasonable chances to get out of poverty or a cycle of problems. REASONABLE being the defining word.
While I vehemently disagree with the idea of restitution for past societal ills I agree with most of the rest of what you say here. And guess what the common denominator is in all the cost overruns and bloated budgets and wasteful spending you cite? Hint; It's the government. But you sill want them to decide who gets what as reparations or restitutions?