My issue has always been that Picard seems very Captain-as-King in 'tude, which is very retro and not enlightened 24thcentury at all. Whereas Kirk is not afraid of showing his emotions a lot of the time, so while he has his great quiet powerful moments (Balance of Terror, CHARLIE X), most remember stuff like RISK IS OUR BUSINESS from RtT or, more painfully, SHE'S HUMAN! from Requiem.)
Kirk and Sisko (and Janeway even when I was able to watch VOYAGER) seemed military commander-like, whereas Picard vacillated between King and diplomat. The others could incorporate those aspects while still seeming to be in the service, but Picard ... well, suffice to say I'm not a fan.
Po-tay-to, po-ta-to. Both men are different commanders, jut like both are different men. This doesn't mean that Picard has no emotions or won't smile or express his feelings, he just does it in a different way. At least Picard cried his eyes out when it counted ('Sarek' and Star Trek: Generations
, ). Kirk (or rather, his savage half) only shows real emotion when confronted.
Q WHO and TAPESTRY and the end of ALL GOOD THINGS show promise at what COULD have been with Picard, but I have always seen him as a missed opportunity. (also kind of wished they HAD let Q serve as their Exec for awhile, because 1st season Riker was such a damned tourist!)
Having an arrogant God-being serve as a member of the crew of a starship would have been a cheat, especially since said being (Q) had a lot to learn than he thought Picard did (as shown in the latter two episodes of Voyager
he was on.) As for Janeway, she's the first female captain ever on a Star Trek
show; having her act like a typical female in the emotional department would have been disastrous, and would have gotten a ton of nasty mail from a lot of female Trek fans, telling the producers that she should toughen up.