I think what Uvtha means is that if you spend say 2 weeks of personnel time (at an average salary of 50K, that'd be about $2000.00) developing a piece of content, but that content is only accessible by say .01% of your customer base, then you've spent ~$2000.00 without impacting 99.9% of your customer base. Or, you could spend the same ~$2000.00 on content accessible to 100% of your customer base, thereby impacting your entire customer base in a positive way. The latter is probably a better investment from a business standpoint. Yes, the .01% might be impacted substantially by the first scenario, but it's still only .01%. You can increase/decrease the numbers a bit, but the general point is probably still valid for UO at this point in its lifecycle.
Spending 20 years with a game should be acknowledged and rewarded by the studio that supports it, not ignored "'cuz there's so few."
They can do a new reward for every 5 years past 15, so that won't amount to a great deal of work. The other years past 15 can be increased picks.
However, 20 years is kind of a milestone. Some token of recognition for players who reach that milestone would be nice.
Also, and sorta on topic, isn't there a title only available to 18 year accounts?