I have had a response from Elections Canada to my rant:

Thank you for taking the time to write to us. We take note of your concerns. The dates for advance polls are not discretionary but are instead set by legislation, based on polling day. Subsection 171(2) of the Canada Elections Act provides that an advance polls shall only by open on Friday, Saturday and Monday, the 10th, 9th and 7th days, respectively, before polling day. Since polling day is May 2nd, advance polls were therefore required under the Act to be scheduled for April 22, April 24 and April 25, 2011. Please note that Elections Canada does not set polling day. Pursuant to Section 57 of the Canada Elections Act, polling day is set by a proclamation issued by the Governor in Council (the Governor General), unless it is a fixed election date. Electors have other options which we hope will accommodate their circumstances. They are invited to contact their local Returning Officer (RO) office who can provide electors with information on what their options might be (if they live close by, they could vote in person at the RO office, if they don’t they can also vote by mail), and the staff in the RO office can explain these options and how an elector goes about exercising each one. For the contact information for your local RO office, check our website at the following link and enter your postal code: http://www.elections.ca/scripts/pss/finded.aspx?L=e You can also call 1-800-463-6868 and they will put you through to the local RO office. We regret that we cannot give you a more favourable response.