While $50/year/account may appear a bit steep I have looked at my current annual statements. For my RRSP I am paying well over $300 per year in commissions with TD Waterhouse and I consider myself rather an investor than trader. I mean - sure, I would probably trade a bit more if it was cheaper. Look, a simple purchase of some stock plus selling covered call on that position is $9.99+$9.99+$1.25/contract with TDW. So, it is at least $21.23. I have a margin account with IB and this sort of transaction may cost somewhere around $5 or more - but would rarely reach $20. Not to mention the $43 exercise commission with TDW that kills many deals. Think about it - $21 + $43 = $64 just to exercise a very simple trade that makes you some money over 1-2 months on a covered call in one of the good scenarios. RSPs are usually relatively small - a large RRSP can be around few hundred thousands at most and TFSA - we are talking about dozens of thousands. Not talking about small number of investment gurus here

So, transactions like this, buying few hundred shares of a company and selling the covered call to make few hundred dollars may be quite typical.
Checked the annual commissions for TFSA - same story, way over $100. And this is, again, considering that I could not do some trades in that TFSA because it was not practical.
I think that even with $50/year I may be saving money on commissions with IB. Will seriously consider to switch. Big bank's brokerage commissions are way too high.
Also I think IB will readjust their strategy for RSPs in the future. I think they are doing it not so much to make tons of money, but rather as additional benefits for existing customers. I may be wrong but personally I do see the value of keeping the investment accounts with as few firms as possible.