Beyond unlimited downside, why is shorting structurally harder than going long?

How to answer

Headwinds stack: (1) equities have a long-run upward drift, so you fight beta; (2) carry costs — borrow fees and dividends owed; (3) timing matters more — being right but early can stop you out; (4) the ecosystem supports the stock — management, sell-side, buybacks, optimistic guidance; and (5) negative convexity — winners shrink your exposure while losers grow it. Being right on fundamentals is necessary but not sufficient; you have to survive the path.

Key idea: Only citing 'unlimited downside.' Strong answers cover drift, carry, timing, ecosystem incentives, and convexity.