When you book a Blue Basic fare, you are JetBlue's last priority - even if you are a Mosaic. They have no obligation to give you a preferable seat. By keeping empty rows, it gives the gate agents a lot more leeway to move people around as is often necessary at the gate (e.g., for families to sit together, for those whith special needs who may benefit from some extra space, to help Mosaics or even partner elites who have purchased
real tickets, to help standard TrueBlue members or even non-members who have purchased
real tickets).
See the below, abbreviated chart which shows the difference between JetBlue's fare classes (
source):
From the same page, pay specific attention to note #6:
Originally Posted by JetBlue Airways Corp.
6. Mosaic 1 members can choose an EvenMoreŽ seat selection for free at check-in and Mosaic 2, 3 and 4 members can choose an EvenMoreŽ seat selection for free at time of booking (pending availability), excluding Blue Basic fares.
Further down, there is a section titled "Do Mosaic benefits apply to Blue Basic fares?" Your specific question is answered there:
Originally Posted by JetBlue Airways Corp.
Blue Basic customers (including Mosaic members) may select seats at any time for a fee. If you don’t, your seats will be assigned before departure.
TLDR: seat selection is available for an additional fee with Blue Basic. If they are moving you as a Mosaic, it is simply as a very generous courtesy and should absolutely not be expected every time as they have no obligation to do so per the terms to which you agreed when booking.
Blue Basic was designed to compete with ULCCs like Spirit and Frontier. If seat selection is that important to you, pay for a better seat, pay for a better fare, or pay to take a different airline.
The answer will not change, even if you start a new thread on the topic. Does it suck? Yeah, kind of. But this is not the first time you have mentioned it on this forum. Can we please stop beating the dead blue horse?
-J.