In a PM I responded to a member about this issue. Some of you might find portions of the response of interest.
... I remember when my own feelings were exactly the same as you mention. The conventions actually HAVE been in Texas before. Twice. And I've thrown my vote in to the directors that I thought another one was due here. But in order to have a convention in any particular location, we have to have a convention HOST. The Host has almost two years of prepratory work to perform setting up Hotels, Tours, convention halls, getting local business sponsors, etc. etc. Then when the convention actually occurs, the Host must be the business manager for the entire week's events, having already spent at least the entire week PREVIOUS getting final set-ups performed. This invades and takes over the Host's entire life for quite some time,....and it pays nothing. It's entirely volunteer. (Think about the demands upon YOUR time, if you voluunteered to do this.) If you've ever participated in a nation-wide organizational convention, you'll know what I'm talking about.
With regard to (your) feeling that the only way to arrive is in a 170, you might be interested to know that most convention attendees actually arrive via airline! Many feel that weather and other concerns are too great to risk the investment in hotels/tours/etc. That's not my feeling, but it's apparently the way many feel. (Plus I suspect some wives just don't want to ride in a small plane with their spouses.) Personally, I don't feel having a "beautiful" plane is a requirement. Most 170's in the fleet are either well-worn workhorses or otherwise show their age. I find them ALL simply beautiful! I love 170's no matter how they're dressed, and no matter how they're used! I
like seeing them
and their differences.
Also, I'd never want to miss out on visiting with other 170 owners/enthusiasts simply because their airplane wasn't out at the airport. The majority of the time spent at conventions is with the people, and seeing the tours/sights, ...not the airplanes. And many members are actually retired persons who either use a RV for the vacation journey, or may no longer actually own a 170. (Many of our members have never owned one....they simply admire the airplane. Some of our members are spouses/descendants of deceased former members who made strong friendships years ago at previous conventions, and wish to continue the great comraderie and good relationships formed long ago. I was personally surprised and pleased to meet some of these very interesting people, and Jamie and I now exchange cards and letters with several of them, and look forward to seeing them again later this year.)
Bottom line: There's lots more to this than first meets the eye. Conventions sites revolve around a lot more than simply a convenient location. (And what's convenient for one, is inconvenient for hundreds.) One of the most important requirements is a Volunteer Host. (To volunteer, contact the President of TIC170A with a letter including all the reasons you believe your site will be an attractive convention site, and should be considered over/above any others for the proposed year, and describe the efforts you are willing to make to ensure the success of the convention.)

I personally believe an excellent site would be New Orleans, (with it's D-Day Museum). But we don't have any volunteer Host from there. At least not one that has spoken up.
...
So,...you see..., it's not all that simple.
Regards,
George
An issue I didn't mention in the above response, is the problems faced by a convention host in getting local airport authorities to even
allow a convention! Many airports don't want, aren't insured, have prohibitive regulations that prevent conventions from being held at their airports. This can be for many reasons including parking space, visitor arrival/departure handling, security concerns, insurance risks, etc. Call your local airport manager and tell him you want to invite a hundred or so taildraggers to come and take up the ramp spaces and tie down for a week (free, of course) and don't want to pay retail prices for the 20-30 gals of fuel that'll be sold see what he says.
We owe a huge debt of gratitude to past and future convention hosts for the hard work and personal sacrifices they all go through which frequently end up in unwarranted criticism.
(As a sidenote to all regarding central locations, past conventions have been held in CO, IL, WI, TN, PA, MO, IA, and AL, some locations several times, as well as all four corners of the US. You want a convention near you? Volunteer!)