By those definitions, entryism is better, sure, but electoralism isn't bad. Look at the Sanders campaign. Running, even without winning, did a lot for the left, making that campaign useful in terms of entryism. But had he won, of course that would be good, too, so it doesn't really make sense to say electoralism is useless.

Also, there's the argument that you can't do serious entryism into electoral politics without a bunch of people who are genuinely seeking power through that election (i.e., electoralism). If you just throw your hat in the ring and don't try to run a serious campaign you get smoked, which is a bad look and can discourage people as easily as it can radicalize them.