sigh There are certainly judgemental Jews–I left my childhood community because of them–but the Christian “Old Testament” is not the Jewish Tanakh, which consists of the Five Books Of Moses, the Prophets, and the Ketuvim (Writings), plus the Oral Torah [1]. The Christians reordered the books, ignored the Ketuvim, and, this is key, didn’t take any of the commentary and scriptural analysis with them when they split off, and especially didn’t take the Jewish traditions of actually interrogating and cross-examining the text with them either.
So they’re missing the entirety of what we call the Talmud, and all of the commentary on how we, as Jews, reconcile with ourselves, the various aspects and commandments of the Jewish god. Instead, the Christian preference, as I’ve witnessed from an outsider’s perspective, seems to be to examine the text on a surface level and to avoid looking for deeper understanding, or deeper concepts, much less any effort at contextual understanding (which often comes back to bite them for their own books as well; in their context, Jesus was a hella rabblerouser and social gadfly [2]).
Also, there are vast swathes of the “Old Testament” that they also handily ignore. My Bar Mitzvah parsha (weekly reading) was this past week; Ki Teizei, and it’s chock full of such things as, oh, paying your laborers on time and in full and a whole bunch of other policies that, while socially backward by today’s standards, were the very bleeding edge of progressivism from the perspective of people in the Bronze Age, which is one of those little contextual points that we like to examine, learn from, and find ways to adapt to a changing world (I’ve seen the instruction from Deuteronomy 22:4, regarding helping with a fallen ox or donkey on the road, be interpreted as meaning “Help out people whose car has broken down” for the modern world).
From a theological perspective, such Christians are actually in direct contravention of Jesus’ explicit instructions (the so-called “New Covenant,” Hebrews 8:6-13) by holding any part of the “Old Testament” as valid, because the 613 Mitzvot of the Mosaic Covenant [3] are explicitly rendered null and void by Jesus for his followers. They’re, again, supposed to stick with the “New Covenant”, which is, again, Jesus’ teachings–which, as we’ve noted, they fail at. Hard.
[1] The Oral Torah was written down as the Midrash when the Romans were trying to break the chain of the oral transmissionand later analyzed as the Gemara; together, they make up the Talmud.
[2] Such as the passages (Matthew 5:39-40) about turning the other cheek and giving up your coat along with your shirt; for the “turn the other cheek” point, in the time of the Roman occupation, striking a servant with the back of your hand was an assertion of dominance; if they “turned the other cheek”, the person doing the striking had to either hit them with their left (and thus unclean) hand, or strike them with the palm of their hand, which was an admission of “you are my social equal”.
The thing with the coat is likewise subversive, as men of the time wore a shirt and an overcoat as daily wear, and suing was something done for outstanding debt collection, so someone being sued “for their shirt” meant that they were so destitute that the only thing they had left with which to pay was their clothing. However, if they gave up their shirt and their coat, then they’d be publicly naked–in a culture with a strong nudity taboo. In effect, Jesus was instructing his followers, “Okay, if they’re going to be so utterly greedy, cause a public scene and make it very clear that the cause of this scene is because this person is so greedy”–and, if the debt holder accepted the coat, then they were accepting the violation of the nudity taboo as well, or, alternatively, had to make the public spectacle worse of trying to give back the naked guy’s coat in front of the assembled rubberneckers.
That’s the kind of context that I usually end up seeing ignored by Christians when examining their own holy texts.
[3] Said Mosaic Covenant is something which the Jewish people still hold as valid, I wish to point out; we just tend not to be utter dicks about it, due to the scholarly tradition, although exceptions are definitely widespread among my people 
