I think it would not dilute power, it would instead concentrate more power to governors.<quoted text>
The founding fathers wanted the senators to truly represent their individual states - and as the goernor is their de facto 'president', it was left to have the governor represent their interests. They forsaw the potential for the current abuse we see in the 'elected for life' senators we now have and felt that governors appointing them - making them work at the pleasure of the governor and they stae they represent - would dilute the power.
How about a constitutional amnendment for term limits. That would diluite power.