The situation you're referring to is seasonal abuse of the EI system where employers pay salary during the season and then lay them off at the end of the season, after which the workers collect EI until the next season starts. This works largely because those workers work sufficient hours during that period to qualify for EI. "New" workers are seldom if ever hired to replace those laid off workers as there's simply no work to do.
As a side note, this abuse is in no way limited to the Maritimes. You see exactly the same sort of abuse in any seasonal industry in Canada (see: oilpatch).
EI reforms have been slow and have met with extreme resistance from both social and business groups. If you want to draw coarse circles around issues, then a big one is the blanket EI system that operates with so few parameters that allow this sort of abuse.