You keep making a big deal about the lack of a Modern Orthodox Chumash [the five books of Moses with commentary]. Here’s the real story.
First of all, a Chumash like that uncovers the widening divide between Left Wing MO and Right Wing MO in respect to the academic study of Torah and how far you can deviate from the Rambam’s 13 principles of Jewish faith. Someone who is LWMO will want the chumash to discuss variant texts and the possibility of post-Mosaic verses. He will also want to quote academics like Robert Alter and even Christians. Someone who is RWMO will fight tooth and nail against such a chumash and will only want traditional Jewish commentaries quoted.
Second, there is the issue that most MO scholars are academics who have great difficulty connecting with the average layperson. Rabbi Hertz only allowed pulpit rabbis to write the commentary to the chumash he edited because he wanted it to speak to the layperson. MO scholars generally don’t know how to do that. There are a few pulpit rabbis who do but they are overworked. Roshei Yeshiva don’t have the specialized knowledge to write such a commentary nor the ability to connect to laypeople. So who’s left to write it?
Third, most MO scholars are interested in philosophy and law, and not Bible. That’s why these difficulties haven’t been overcome yet. Rabbi Norman Lamm has been a major driving force of the MO intellectual community and this is not his area of interest. However, people started working on projects like these about a decade ago, albeit without success.
There is currently a chumash being written in YU but insiders are saying that it will be too academic. Rumor also has it that Chief Rabbi Jonathan Sacks is working on a chumash that will use his great eloquence to dance around divisive issues. I think he’s probably the only person alive who can do it successfully. There is also a MO chumash in Israel that is supposedly being translated to English that I believe is pseudo-scholarly and accessible. And the MO but boring Daat Mikra series on all of Tanach is being translated as well.