Rightly said, and fully agreed, however, there is catch! 
As is said:
"... Jaagday Raina, Saaday tey na Raina... ", following is written in the products technical data sheets, and they are taking no responsibility:
Amsoil OE Synthetic Motor Oil:
SERVICE LIFE:
In gasoline-fueled vehicles, AMSOIL OE Synthetic Motor Oil is recommended for the intervals stated by the vehicle manufacturer or indicated by the oil life monitoring system.
(Source: https://www.amsoil.com/lit/databulletins/g3404.pdf )
Amsoil XL Synthetic Motor Oil (for 12,000-miles or one year, whichever comes first):
SERVICE LIFE:
In gasoline-fueled vehicles, AMSOIL XL Synthetic Motor Oil is recommended for up to 12,000 miles/one year oil change intervals, or longer when recommended in ownerâs manuals or indicated by electronic oil life monitoring systems.
(Source: https://www.amsoil.com/lit/databulletins/g1404.pdf )
Amsoil Signature Series 100% Synthetic Motor Oil (For up to 25,000 miles, 700 hours of operation or one year, whichever comes first):
Do not exceed 12,000 miles or one year with other brand filters unless longer intervals are recommended by the vehicle manufacturer.
(Source: https://www.amsoil.com/lit/databulletins/g2880.pdf )
Issue is, people do not bother to go in to the details. They just rush by looking at the physical appearance and appealing looks of the things, and get their engines ruined and damaged, and when they rush to claim the damages and warranties, engine oil companies will not take responsibility. Its also the duty to general public, to do some homework, instead of falling prey to such marketing gimmicks, traps, etc.
Amsoil is also not wrong in their place. It is clearly mentioning to only drag up to 12,000 miles, or 25,000 miles, if mentioned in the owners / users manuals, and as per my limited knowledge, I have not come across any passenger vehicle manufacturer, which recommends drain intervals of 12,000-25,000 miles, or 01 year, or 700 hours of continuous operation (whichever comes first), despite having may be larger oil sumps (Yes, they have mentioned to observe engine oil level regularly, and top up when reqd.).