You can offer them more money, better work/life balance, a more fulfilling job, etc. When the government allows the hiring of foreign workers on visas, it's tilting the playing field in favor of employers. Why offer a better wage when you can just cry to the government and get an indentured servant at a discount?
Exceptional talent is a different argument - most H1bs are average at best. Claiming to be unable to hire for an entry or mid-level software engineer job is absurd.