The environmental, social and governance movement could weaken the performance of companies that have already done a lot of good for society, Commissioner Hester Peirce of the U.S. Securities and Exchange Commission said in an exclusive interview for the latest episode of ESG Insider, an S&P Global podcast.

Peirce said she worries some managers use companies as their "personal piggy bank" in the name of fulfilling social objectives and she worries that trend could grow as millennials move up the corporate ranks. "I have nothing against millennials and I think it's great they're passionate about a lot of causes," Peirce said. "But I think we shouldn't throw the valuable corporate form out the door at the same time that we're realizing that there are a lot of things that are important in life."

The SEC is considering changing the rules underlying the proxy process in which companies hold annual meetings with investors each spring. At those meetings, investors vote on key governance issues and sometimes on resolutions that shareholders have submitted.

"We want to get the calibration right so that some shareholders are not subsidizing the pet issues of a few smaller shareholders," Peirce said.

The agency has indicated that it could propose rules on the process as early as spring 2020, including potentially related to the thresholds for submitting and resubmitting resolutions and regarding influential proxy advisory firms that many asset managers use to track and vote on resolutions. But shareholder rights advocates worry raising the threshold could hinder their ability to get emerging issues on the radar of company boards and management.

Sanford Lewis, a lawyer and director of the Shareholder Rights Group, in the podcast contends the current resubmission thresholds are working fine and points to examples of how shareholders rejected fringe issues in annual meetings this year.

In the interview, Peirce also noted that she is mulling options for pulling the SEC entirely out of the process of answering companies' requests to block certain shareholder resolutions that the companies argue are not permissible under the agency's proxy rules. We talked with Tim Smith, Director of ESG Shareowner Engagement at Walden Asset Management, about the potential that the SEC will stop weighing in on resolutions, and whether companies and investors are clamoring for that change.

The episode also dives into how climate-related resolutions played out this year at key energy companies including at BP PLC, Royal Dutch Shell PLC, Exxon Mobil Corp. and Chevron Corp.