I persuaded my little brother to get a Moto E 2nd gen over a Sony Xperia E4 as a first phone because I presumed that there would be an update to Marshmallow. Very disappointed in Motorola, the Moto E 1st gen received more support.
Your entire post does not make an ounce of sense.
http://support.sonymobile.com/global-en/xperiae4/software/
According to Sony's website, Xperia E4 is still on freaking Kitkat 4.4.4 that was last updated on 06/26/15.
Moto E 2nd gen has been on Lollipop 5.1 Since May 14th.
If Sony can't update the Xperia E4 that you "regretted not letting your brother get" from Kitkat 4.4.4 where it is today to Lollipop, what makes you think Sony would have updated it to Marshmallow?
So you're disappointed in Motorola, but you're not disappointed in the Sony equivalent? Your extreme bias is showing here. :hmm:
Again, most Android OEMs don't update their cheap $100 phones(as we can see from the Sony Xperia E4 example here). Motorola is pretty much one of the only one that does(and they still do today), so I'm not sure why people are throwing their arms in the air regarding the Moto E 2nd gen not getting Marshmallow when they should be thankful that it's still not on Kitkat like the Xperia E4 that your brother wanted to get.
Show me a $100 Android phone getting upgraded to Marshmallow and we'll talk. Otherwise, Moto is still far ahead than other Android OEMs when it comes to Android updates on cheap phones.