This seems to be mostly in keeping with the spirit of index funds. It's a hands off approach that lets the company run itself.

In theory an index fund should never own that much of a company, because that means it would own >50% of all publicly traded companies. The whole point is to spread the risk evenly so you can realize the average returns without having to put any thought into it. It shouldn't mean it's buying $100k shares of GE and also $100k shares of Mom&Pop Pickle Fork Inc.

Not only that, it doesn't account for short sellers. Index funds will happily lend their "passive" shares to anyone (i.e. short sellers) willing to pay interest. So if prices start to rise as someone tries to buy 5%+1 of the shares, others will rightly determine that the shares are now overvalued and start selling them short (especially if the buyer is expected to harm the company), allowing the buyer to keep buying at a minor premium over the original price. Or even at a discount, if the purchase is seen as inevitable and the damage they're expected to do gets priced in.