I think it depends. I think long-term investors should still look at short interest and read short thesis to understand counter-arguments. Regarding manipulation and herding, I think it depends. Someone could short Apple on merits of valuation. In this instance, due to the company's strong balance sheet, its a matter of debate and opinion among longs/shorts as a short report will not death spiral the company. In situations where a company has a significant among of debt or a cash flow issue or is a financial company, the company generally has to access capital markets at some point in the near future. This is the danger of leverage, or even proving a business model as a public company.

In the middle ground, you have a company like NFLX where some investors like Bill Nygren are long and advocate the position due to his belief the company has room to raise prices in the future from say $12/month to $15/month, shifting the PE ratio from 150 to 20. My assumption would be that a short thesis would have much less impact on scaring the market to instigate a death spiral for NFLX.

So with Telsa, it is in a vulnerable position due to being in a highly capital-intensive business, negative cash flow, and significant liabilities. But, it also is the only car company ever to presell hundreds of thousands of cars and a CEO who has delivered on big visions and promises before.

I have no personal investment in Tesla, but I hope Elon succeeds as I appreciate his ambition.

Unless you want to buy more shares from the shorters or liquidity from the traders. Markets need sellers and market makers.