They sure have...
The SR-71,
U-2/TR-1
Have Blue
F-117
C-130
C-141
C-5
S-3 Viking
P-3 Orion
F-104 Starfighter
Constellation
L-1011
P-38 Lightning
Blk 60 F-16
Blk 70 F-16
The JASSM
The Javelin anti-tank missile
The MLRS
The LRASM
oh, and lest I forget,
F-22
just to name a few things Lockheed has "effed up".
Those things were then and this is now.
Yes, once upon a time they did some really good work but they are making a career out of the F-35. A few of those are not Lockheed but General Dynamics legacy.
They lost my respect when they lobbied against their own aircraft, the F-22, to save that money for the F-35 because it has or had a higher profit potential. And that is what they have really screwed up.
I kow people who began post military careers working on F-35 code and have since retired a second time and are now off to yet another job.
The F-35 is a poorly managed program.
The F-22 is 30% built by LM, with Boeing building about 30% as well.