Unfortunately it would seem that a minority of these "contractors" have tarnished it for the rest. Hard landings, experience levels that are not commensurate with stated hours, poor flying, cavalier attitudes to SOPs, various incidents, inability to speak intelligible English and various acts of unprofessionalism that we haven't seen in the airline before have put many of the captains on edge and made for a long day. This has probably spilled over to give rise to the comments above. From what I hear there have been a number of good ones that unfortunately weren't offered a permanent position due to the nature of the HR beast that rules so many of the worlds airlines these days. Flight operations would have offered them permanent positions in a heartbeat as they are a known quantity but aren't allowed to.
Contrary to popular belief it's actually in the unions interest to have a certain level of FO contractors as it reduces the risk of anyone on the seniority list being chopped when the next downturn comes.