Good question, weak answer... I think it's mainly due to the SmartGWT GUI being realtively new and that level of review not yet being prioritized. The sorting needs to be set pretty much view by view, and there are a lot of views. Also, your suspicion that sorting on certain fields, like ancestry, is correct. It is made mode difficult in that the underlying value is encoded. So, sorting on that column would be limited to client-side only (i.e. only the data fetched ths far) and can not be performed in the actual query.
I agree that there should be better defaults, typically 'name'. Also, as you point out, sorting choices are not yet persisted for a user. This would be a good RFE. And yes, column widths are pre-set and not always perfectly. Columns are not "shrink to fit" for technical reasons, but rather fixed-width. Again, persisting preferred widths for a user could be useful.
My only recommendation would be to fomalize specific requests as Bugzilla entries so they can get prioritized. Of course, if you feel the desire to submit patches for your most annoying views that would be great.
After discussing this I was annoyed enough to actually create https://bugzilla.redhat.com/show_bug.cgi?id=846375 and at least fix a few glaring issues with the resource list views. I've pushed this for RHQ 4.5... Feel free to file further BZ's for your related requests.
Thanks for adding this minor but important feature. I will probably file some bugs once I get to try and deploy RHQ 4.5.
I created https://bugzilla.redhat.com/show_bug.cgi?id=850976 for suggesting that alert, metric, and drift templates should appear sorted.
I haven't tested your fix above but are groups also now sorted? That is probably the other big one. I have about 30+ groups and they all appear unsorted.