That's the real of benefit that has been lost with this announcement, it's not the MAD flights but the early morning departure to LGW.
That 0830 flight got you to gatwick before 11am, giving you plenty of time and opportunity to complete your onward travel or valuable time on your day of arrival.
However there was a major flipside - the loss of the evening return to LGW (because the aircraft was overnighting in GIB after the MAD run) - was hitting many of the business day trippers (who lets rememebr are usually paying a decent ticket price).
Regarding the GIB-MAD-GIB service, its easy to see why it caused GT so many problems, unlike IB who are operating it as a short run from their hub this was a continuation leg.
Apparently the way GT are currently running it two crews overnight on the rock at a time? (The crew doing the GIB-MAD-GIB run would not fly it back to LGW in the morning, another crew would do that, they'd wait for 0730 LGW departure to arrive at 11+ and then fly that back?)
As such, due to their late night slots at MAD, when there was a delay or problem pushing them past Gib close time or a weather divert all crews were in the wrong place, not just the passengers.
So if you want to fly from GIB your earliest depature will be after 11 again....
----
There is also talk of IB involving their franchise partner Air Nostrum in their GIB services. Possibly to restore the twice a day service following GTs decision to suspend.