You and your employer have a simple arrangement that you provide him with your time and expertise and he pays you an agreed amount every month for your trouble. You aren't marrying him. That contract can be terminated by either party under a variety of circumstances. Neither of you should expect some kind of loyalty to stay with the company. Don't believe for a minute that your employer wouldn't let you go if he had to or wanted to.
This is your career and your life. If it comes back on you then you explain that you are looking to earn your full potential.
There is an old adage in sales. If the customer wants to buy your product then the only thing that's stopping him buying it is the price.
You're the product. You need to be happy that your are being paid what you are worth, otherwise it will eat you up from the inside every day you get out of bed.