That is a strategic option. Given the interplanetary shuttle capacity Earth has now (read: zero), doing one-way trips is the quickest and less costly way to find if Mars can be settled. Volunteers are told they would be risking their lives, because doing round trips is unfeasible yet.

Establishing round trips from Earth to Mars would need several Space Xs to finance it, or that the current one thrives for some decades more. Governments are not interested on it if it doesn't translate to votes.