Well, I guess that's a real matter of personal preference then, because I personally thought the N900 was perfect in it's size, including the keyboard I'm a big guy (1.95m) with big hands, by the way.

How do you read 'develop your own OS' when I say 'free bootloader to load whatever you want'?

I wonder, have you followed the development of the Neo900, and do you know why so much effort was put into separating the memory used by the phone's modem from the memory used by the CPU/rest of the system? It's because the modem is running on a proprietary software blob of which you do not know what it does. We have no choice but to use it however, otherwise you have non-working modem, and thus no telephony functionality. The modem might read shared memory, maybe influence it as well. So, your assumption is right: I do not trust the software stack. Hence why the Neo900 was attempting to detach/sandbox the modem as much as possible, as Purism is doing with it's Neo900, and built in hardware kill switches as well, as both Purism and PinePhone are doing.

I find your manner of thinking strange. It's the same as: "why include a 3.5mm headphone jack? I won't use it anyway". Sure, but maybe other people would? If you don't want to use hardware kill-switches, simply don't.