If you assume you have no edge, then spread will eat the account. A good example would be taking random trades, long or short on the toss of a coin. You'll win some, you'll lose some, and over a sufficiently large sample size you'll break even. In that scenario the spread will eat the account.
Although people don't like to admit it, the majority of technical based systems are no better than a coin toss in terms of edge, and therefore, they suffer the same fate.
Most new traders perform significantly worse than a purely random system, and their own incompetence is generally a bigger factor than the spread.
Spreads are the brokers edge, and its a MASSIVE edge, and overcoming that edge is far more difficult than most here would care to acknowledge.
Equivalent to the '0' on a roulette table is essentially what you're saying?