Shatner established Kirk having a certain charming over-the-top-ness, which I guess is what you interpret as comedy, which isn't surprising - there's a good reason why Shatner's Kirk has been parodied so incessantly. But without that element, we no longer have Kirk. It's like expecting Spock to not have that barely-hidden arch sarcasm or McCoy not to fly off the handle every so often.