Better for the company, better for the employees, better for external speculators.
A stabilizing bid by the underwriter is effective market manipulation that pretends there is more demand than there really is. It can be retracted at any time as well. Outside of an IPO this is illegal.
They can keep the confidence game going for 90-180 days, and the other aspects of an IPO are better for the company since there would be no reason to sell even more shares since they sold a piece of the company at a highest valuation to the banks in the IPO.