The government is having a difficult time attracting talent due to the month-long shutdown that ended on January 25. House interns have not been paid yet because many departments, namely the Administration Committee, are still backlogged from its recent hiatus. To increase their talent pool the government realizes it has to expand the opportunity to include individuals who need to work for a wage, and not just limit it to those who can only work for free. The issue of recruiting and retaining talent may be further exacerbated should another shutdown occur later this year.
See "Shutdown Harms Federal Hiring Efforts", Patricio Chile, Bloomberg Law, February 8, 2019