It is widely believed that modern (small 'm') yeshivos essentially conspire to suppress Tanakh. Why? Because Tanakh can buttress Zionism. Because Tanakh can buttress Christianity (well, a couple of billion people think so). Because Tanakh is at odds with many contemporary yeshiva world norms and values etc. This is one of the constant complaints of, variously, neo-maskilim (and the non-neo ones), Karaites, Christians, Zionists, religious or otherwise and more. The feeling isn't necessarily confined to a critique of the yeshiva. It's also thought of about the general public.
Okay, that's a bit of a caricature. Plenty of people don't go so far as to believe in a conspiracy. But the feeling is widespread that they or we don't know Tanakh, that they or we are uninterested in Tanakh etc.
The truth is that there is enormous ignorance of Tanakh. Ask your average yeshiva bochur (or adult) what the theme of Amos is. Your average response will likely be somewhere between glazed eyes and something about teshuva or maybe avoda zara or mashiach. This is an anecdotal assertion, but come on, you know it's true.
From the perspective of the yeshiva this type of charge is really annoying and unfair! For one thing, they know its untrue. In yeshivos there are often parshas ha-shevua sedorim (even small ones). The bochurim are expected, as benei Torah, to do shenayim miqra ve-ehad targum (although no one is checking). There are more than a few genuine Tanakhic experts in the yeshiva world, and I'm sure most people you ask know people who really do know Tanakh. In yeshivas they themselves criticize the ignorance of Tanakh. The attitudes of people like R. Ya'akov Kamenetzky towards Tanakh is widely known and repeated. A true talmid hakham worth his salt will be able to quote not only all over Chazal, but all over Tanakh as well. The popularity of parsha sheets from people like R. Frand. The weekly nabhi shiurim by people like R. Reisman.
In short, it incenses the yeshiva and the haredim (sure, why not, even though this is the first I mentioned them) to be charged with not studying Tanakh, not knowing Tanakh, suppressing Tanakh. They don't think they're doing that at all, and there is all the evidence to the contrary! The know and believe it isn't true. And yet, it is also true that it really is de-emphasized, even if inadvertantly and even it unconsciously.
There are a variety of reasons for this, some historical, some practical. Firstly, it should be recognized that this isn't a modern issue at all. This goes back hundreds and hundreds of years. In some measure the de-emphasis of Tanakh happened with the rise of an emphasis in the Talmud. We are, after all, rabbinic or Talmudic Jews. It's true! Secondly, its possible that the over-emphasis on Tanakh by midieval antagonists like the Karaites reinforced this. Certainly we know that the rise of the Jewish haskalah and its emphasis on diqduq and Tanakh did in fact inspire a reactionary opposition to these disciplines. There is the matter of time management. Although it seems axiomatic that Tanakh is at the top of the Jewish intellectual food pyramid, there is only so much time and so much one can learn. There is no way for average people to become a Tanakh expert while becoming, for example, a Gemara expert. Although I understand that in some yeshivas Tanakh study is actually openly ridiculed in others it is just assumed that the good bochur will learn Tanakh somehow (and I'm not even going to get into "higayon").
In short, there is no conspiracy. But on some level there is some truth to the feeling that many people have.