I like the 10 ML seasons threshold too. Otherwise too many guys worth consideration will miss being eligible due to things outside our control (IP/AB missed due to injury, player age when the world started, converting a starter to a reliever, etc...)
However, on the other hand, MikeT23's observation alarms me. I don't particularly care if someone nominates a guy for some stupid reason (funny name, same hometown, whatever), but in the case of new owners, you might see someone nominating a guy because he thinks its funny, while ignoring people that played on the franchise before he took over and deserve legitimate consideration.
(Of course, thinking about it more, owners that would do that aren't serious enough about HBD to stick around for more than a couple of seasons anyway. And with eligibility preserved, I guess that would free the next owner up to nominate that deserving player.)