I'll give you an example:

I would like to see more pointing out that most members of Parliament, government ministers and heads of city halls from the two main parties are also "housing investors" so it makes absolute sense that they voted for all kinds of measures over the last decade that pumped up even higher the gigantic house bubble in Portugal, which is making young people in Portugal stay with their parent's until their mid 30s and, in a country with one of the most aged populations in Europe, delaying childbirth and having fewers children, and even to leave the country by their hundreds of thousands each year.

Instead all we get is something around "house prices are too high that's bad for the young" and only started getting it recently when even the Middle Class started hurting - I mean, the guys at the mainstream parties also say that at this point because it's got the a level were it's well beyond undeniable. I mean, I moved back to Portugal 5 years ago from the UK and it was already painfully obvious to me that there as a massive housing bubble and the politicians in power were passing measures to pump it up even further and faster.

Similarly the non-mainstream Left seldom talks about Corruption and the systemic structural reasons for it (from a Judicial system which is slow, underinvested in and partly subverted by the dominant political parties, to a widespread nationwide culture of Nepotism and Cronyism), not least because the party with the biggest problem in that domain at the moment is the supposedly leftwing mainstream one with whom these parties aimed to make a cohalition in the last Parliamentary elections. Refraining from overtly and unwavering standing by the principle that politicians abusing the powers they've been delegated to by voters in unacceptable no matter the party of those politicians at the time when the far-right was (with tremendous hypocrisy) was making a lot of noise about it, just made those leftwing parties look like either accomplices, unprincipled and/or just looking to feed of the tit of the state like the rest.

(It also doesn't help that in my experience those leftwing parties also internally suffer massivelly from Cronyism and Nepotism)

IMHO to be a proper leftwing party you don't really need to go around calling other people assholes, you just need to point out that many if not most of the greatest problems that affect all society weren't born from immaculate conception: they are the result of choices and actions for personal gain of people entrusted by voters with powers that can impact everybody else. Merelly "This is bad and needs changing" from the mouths of a politician with no pointing of fingers doesn't mean much because they all say that when things get to the point of being undeniable, even the very same politicians that caused that problem in the first place and such stuff only real works for tribalists who are already convinced that "the leaders of my Party are trustworthy and it's those other people who are not" (which has the curious effect of making most party members thinks those speeches are amazing and insightful when comming from those they see as they leaders, without noticing the deep similarity with what is said by the leaders of other parties, even while outsiders and non-tribalists are hearing everybody saying the same stuff and thus not trusting any one group more than another and even thinking "they're all the same").