Anyone who would prefer a modern Android phone over an N900 for anything other than the stereotypical smartphone tasks never appreciated what the N900 actually had to offer. See what I did there? I took your format of:
[sweeping generalization of people's preferences], [dismissive acknowledgement of reason deemed 'acceptable'], [insulting dismissal of all other reasons for that preference]
..and reversed it, albeit with a little less condescension and asininity.

Anyway:

There are no other phones on the market currently that offer everything that the N900 offers. (And I've had plenty of opportunity to familiarize myself with WebOS, Android of all sorts from Froyo to Ice Cream Sandwich, Windows Phone 8, and am about to get my hands on a Blackberry 10 device.) If there is any device that you think really does, point me to it, and in the event that you are right, I will be eternally grateful. More likely though, I will just point out something that I like being able to comfortably do on my N900 that the other devices don't offer.

There are, unfortunately, also plenty of things that the N900 can no longer do or never could do that modern phones excel at. I readily admit that. And I hate that that's the case and find myself using my N900s less and less for things like web browsing and so on. But until a device lets me do all of the things I routinely do on my N900s, with the same or better level of comfort and freedom etc, until then [edit]or until the deficiencies of the N900 become bad enough that they outweigh those things[/edit], there is no viable replacement for me, or for the numerous other people who still use N900s as their main phones or whatever.