I'm not a fan of the word "loyalty'" when it comes to deciding whether to stay in a job. 

Employees need to do the math on a regular basis: Am I making enough money? Do I believe in the mission? Are the people mostly good? 

Many people tend to get comfortable, then tolerate things they shouldn't tolerate, accept below-market pay, and call it "loyalty".

Is a business loyal to you, in return?

Maybe back when there were pensions, but nowadays? 

Unlikely.