I don't like Ben Affleck's Batman. Beyond the numerous problems with the script and characterization, which are very admittedly the biggest problems, I have a really hard time getting past the fact that it's Ben Affleck in a Batsuit or Ben Affleck in a tuxedo in an effort to buy that he's the character. Snyder made a mistake in casting a name for the role because at the time they were cast, every other actor to play Batman in live action hadn't built up a high profile career spanning two decades.
Anyone who has a problem with Robin because they believe that Batman works best on his own either willingly ignores Alfred and Gordon or are seriously deluded about Bruce as a character. Batman worked solo for less than a year in his overall history. There are a shockingly few stories in the comics, shows, games, or other media where Batman is shown to be entirely working by himself. He needs people in his circle.