Fair point, though nobody is obligated to pay a year's salary to a candidate that didn't work out.
The proceedings to jettison a bad hire can take 12 months alone, meanwhile they're still a bad hire being paid.
And if you cant tell whether they are good developer after 3 months, how is an intervoew going to help?
Rightly so, it should be hard to fire people and should require first showing evidence of trying to work together and help in good faith.