Well.... yeah. That's how they use benefits to encourage loyalty.
When I hit 5 years, I vest and my employer begins double-matching, including retroactive contributions. I put in 7%, so in another 2 trays they'll put 70% of my annual salary into my retirement all at once.
It heavily encourages loyalty because it's genuinely a great benefit. I have no problem with that.
I work for money, and the reward for loyalty is more money.