I have a tenor currently tuned with linear Bb. I rather like the timbre and range, particularly for songs in F, as often fits my singing better than G. I could use a baritone instead, with or without a capo, but the Bb tenor is handy, especially early in the day, when my voice is lower—I don't have to change how I play a song, or strain, or capo. And the key of F is more satisfying in Bb or G linear tuning, due to the low tonic.
As for whether a baritone would be better for Bb, the thing is that it would sound like a baritone, not a tenor. I love baritones, but not for everything.
This tuning is called Slack tuning in Louisiana. Cajun Fiddlers tuned their fiddles down a tone to overcome high humidity problems. Add some Cajun songs to your repertoire and you will fit right in when you see someone playing a C accordion.
?? Do Cajuns slack-tune their accordions, too?
And wouldn't a slack-tuned fiddle still be tuned in perfect fifths, rather than anything resembling this tuning (F Bb D G)? Have I misunderstood? Maybe the songs often go down to low F (or Bb), necessitating the lower tuning for ukes?
DIGRESSION:
One thing I'm definitely confused about is what someone means when they say "taropatch", since I've heard it used to describe both reentrant and linear G tuning on tenor ukes and open C tuning (vs. C6) on anything. Now I just wait till they spell out what they mean like Lewis Carroll's caterpillar, rather than trying to second-guess them.