I see no reason dividing your your money to invest weekly since it will still amount to same figure, for example if you want to invest $100 monthly when you receive your salary you can just use it at once than dividing it and still use it to accumulate weekly,
DCA strategy doesn't necessarily mean you most stick on weekly accumulation because even JayJuanGee has also mentioned that anyone can choose whether monthly or weekly depending on the one that's okay for them because even if is weekly or monthly what is more important is your persistent in Bitcoin accumulation by continue to always accumulate Bitcoin on your established timeframe.
Secondly don't think that those who normally accumulate Bitcoin on weekly basis are wasting there time because there are people who earn money on a daily or weekly basis so instead of compiling the money till the end of the month they find it more convenient to use the weekly basis.
When you receive your salary monthly and you decide to remove the one for Bitcoin and then divide it so you can then be using it to invest weekly there's a high tendency that you may even use it for another thing with the hope of returning it which may never happen there by reducing your accumulation percentage for the month.
There is what they called discretionary fund, this is actually the funds that would be left after you must have done all your expenses and there are no more other things that will disturb you then you can use it for your accumulation of Bitcoin, so at this point I see no reason why you should use the funds you had budgeted on your DCA accumulation for another thing with the hope of returning it back because that shows that you are not discipline because an investors who have a goal to achieve on Bitcoin will enever allow anything to hamper there weekly accumulation.