There is a general principle that the answer to "Would this extremely simple strategy make money?" is "No". This is the "no free lunch" or "no arbitrage" rule. It isn't exactly a physical law, but it is a pretty decent approximation of reality. (A more nuanced version is, maybe it can make some money, but only in proportion to the difficulty, risk, and expense of executing the strategy.)
Your strategy as stated is incomplete. You need to say what happens for a stock when the price goes down from the open. Do you keep holding it to close? Or set some stop-loss and sell then? Keep holding it overnight so you don't have to repurchase at the next day's open?
Lets say you do that last version: keep holding. Then consider the results. Classify stocks as "winners" if they generally trend up during a day, "mixed" if they bounce up and down, and "losers" if they generally trend down during a day. At the start of the day you have a portfolio of everything. But you soon sell out of the winners and mixed stocks for a tiny profit on each. By the end of the day you are only holding losers. Do you expect this to outperform the buy-and-hold-everything strategy? I would bet even without transaction costs it doesn't, and with transaction costs it throws away money like crazy.