Ottawa is legislating away a backlog of 280,000 applications made before 2008, saying it's a necessary part of modernizing the immigration system.
Kenney said it wasn't fair to have people wait years for a decision on their application.
"We have to get to a fast system that connects employers with immigrants by bringing them in in a matter of months. We won't get to that fast system unless and until we deal decisively with the old backlog that we inherited and that's why we're taking this difficult but necessary step," Kenney said in Regina on Friday.
Some would-be immigrants announced this week that they will take the federal government to court over its decision to return their applications.
Toronto lawyer Lorne Waldman said he was immediately flooded with emails by people who were furious about the changes. They'd followed all the steps they were told to take to come to Canada, only to be pushed aside, he said.
Kenney said that's not the case.
The minister said those who are having their applications and related fees returned can reapply under new criteria established for the skilled worker program.
"We're not tossing anyone aside. We're simply making a responsible decision to get to a fast system by reducing this huge backlog and the seven-, eight-year wait times," said Kenney.
"Every one of those folks is more welcome to apply for our new and increasingly flexible immigration programs. If they want to come to Canada and they're qualified, they will, and they'll be able to come in more quickly under the new system that we're developing."
The seven-year backlog represents people who applied to get into Canada before Kenney rejigged the federal skilled worker program to fast-track applications from people the government feels can fill holes in Canada's economy.
Kenney said the government stands behind the legislative action to eliminate the backlog, despite any legal challenge.
"In terms of court challenges, we've always anticipated there'd be some immigration lawyers who try to make a buck by suing the government. That happens to us all the time, but we're very confident of our legal position," he said.
"This legislation has been closely examined by the Department of Justice and we believe it's lawful, it's fair and it will survive any judicial challenge."