I am convinced that Adobe could have made Lightroom Mobile read full raws.
Lightroom and ACR support raw files from over 300 cameras...from my Phase One IQ 180 (80MP) down to my Sony RX100 II to my lowly Digital Rebel. So, you really wanna try to process 80MP raw files on an iPad? So, if Adobe released LrM 1.0 to support a subset of the raw files supported in LR 5.4, how do you think Adobe should have triaged raw file formats? Support only the smaller raw files? Only support the most recent raw files?
So, you are convinced Adobe COULD have done this, but pretend you are the LrM product manager...would you support 80MP raws as well as 22MP raws and 16MP raws?
Do you have any idea what the performance would be like trying to adjust an 80MP IQ 180 capture would be like? Do you really think Adobe is stupid? They did what they could do with what they have in the time frame they had to do it. LrM is an "add on" app for subscribers of the Photoshop + Lightroom CC subscribers (or an inducement to join the CC).
Personally, it's no skin off my nose either way...I tested LrM and made my opinion known during testing...LrM is, what it is. Some people may find it useful. At some point in the future when more features are added, others many find it more useful. At this point the only use I'll put LrM to is to see what it's like and then wait till I find it useful for my workflow. Now? Not so much...in the future? I'll see. But as a subscriber, it costs me nothing other than the time it takes to download and install. Again, no skin off my nose.