There are some very nice histories of the French labor movement leading up to the Popular Front, during it, and after, but only one extensive work in English (available online, fortunately). Reading through the demands, almost all of them are things we take for granted today. I mean, paid vacation?
That's not to say that strikes never hurt production or that there was no obstructionism.
Of course, in the aftermath of the collapse, Petain's government (which was very anti-union and saw communists around every corner) and the industrialists had an overwhelming incentive to blame everything on unions, communists, and sabotage. And they got the first crack at writing the history. Later, DeGaulle was struggling with the PCF for dominance in liberated France and post-war. These domestic political contests created more incentives to escape blame and direct it onto others. Participants in this thread have pointed out some of the problems that the manufacturers caused. SAM40.fr has some good work on the rapid expansion of the aviation sector and the number of new workers coming in. This always causes quality problems. Along with pressure to produce aircraft as quickly as possible! So much of what was attributed to sabotage was certainly haste, accidents, corner-cutting, and inexperience.
By the way, I've been going very easy in the PCF. While I think that they've received blame out of proportion to their real influence, I have great criticisms of them as well, not least of which is their lack of policy independecen, taking direction from the Comintern. I am personally deeply disdainful of communism as a political and economic system in practice. Marxism is occasionally a useful framework for analysis, but not as a guide to policy.