Is "finesses wrong for declarer" a good reason to double a (bridge) contract?
Good question. One caveat to what you mention is that with every losing finesse by declarer you are potentially endplayed. If the defensive strength is predominantly in one hand, best not to double; make declarer guess whether the endplay is on or not, as  he may have alternative lines that fail.

Also, there are only specific circumstances in which it is correct to double for a one-trick set. As a double is so informative that Declarer can often play the hand one trick better, double only when you expect to set the contract at least two tricks.

Further, only double when the correct opening lead is already obvious (to you or partner, as the case might be). Opponents who double and then agonize over the opening lead have put themselves in the pickling jar.

The best known (and most common) counter-example to this is in matchpoints when the opponents are vulnerable in a partial that rates to give you a bad board even if it goes down one. In that case one doubles to try and get +200, as the last hope to save the board.