Sure. Poor business decisions are entirely tax deductable as long as your intention is to eventually turn a profit. It is extremely common for business to do poorly or fail.

Most people dont waste money for fun, and the deductions are basically never worth the cost. (why would someone spend 100k on a business to save 25k on taxes? they would still net $-75k)

Also, if you continually loose money over many years, the IRS may question if it is a legitimate business or a hobby for personal gain.