Yes, I'm sure you can. What you are not taking into account is that many people don't have many atmas. Mages generally recommend Minikin Monstrosity. Can you solo/duo Durinn? That is one fight I'd like to see in perle, teal or aurora gear with crappy atmas.
The point is that from a lowbie's point of view, this is the process:
Level a pet job or evasion job to 99 since they might not necessarily have one.
Get mediocre gear for the job they didn't want to level in the first place.
Somewhere in the getting of gear, lots of you recommend magian trial weapons, which take a lot of time, which you're getting for a job you don't want to play in the first place.
Solo/Duo some mobs to get some basic atmas.
Beg/plead/pay for someone to help them kill the higher level, more difficult NM's that drop the useful atmas. (Durinn anyone?)
Kill some more NM's for the abyssites they need to help the cruor buffs and their allotment of time/traverser stones.
Get the bare minimum of useful atmas so they can then try to solo/duo mobs that drop the seals/atmas/+2 items they need for the job they really want to play.
This is a HUGE undertaking for someone who wants to get gear for the job they are actually wanting to play. Once you have your pet/evasion job leveled, geared, abyssite-ed and atma'd, then sure, soloing/duoing is not that hard. This is the process I went through to get to the point where I can now solo/duo some stuff. Thankfully, I ended up actually liking Dancer, though I had to force myself to level nin as a sub. I went 7 years playing this game without touching nin, only to be forced to level it so I could progress through content. I even leveled bst, and have some really crappy gear for that, but my husband has leveled cooking, so I'm able to spam Dawn Mulsum's as my 'strategy'.
Take the challenge, go solo/duo Durinn without an R/M/E/Delve weapon and some mediocre gear. Also make sure that you only use atma's that are able to be solo/duo'd under the same circumstances.
I must say, I find myself increasingly hostile to people who think it's a simple thing to get geared with Abyssea gear via solo/duo/pug's. You tend to forget the large amount of time/effort spent just getting to the point where it's remotely possible.