Why doesn't this script delete all my viruses?

local badNames = {"Infected", "TROLLSZOR", "U GETE POWNED NOOBLUNOOB"}

function isBadName(name)
if string.lower(table.concat(badNames, ' ')):match(name:lower()) then
return true
end
return false
end

for i, item1 in pairs(game.Workspace:children()) do
for i, item in pairs(item1:children()) do
if isBadName(item.Name) then
item:destroy()
end
end
end