Any good reason not to use a WLAN Router......

[Hansoon]

.....to connect, hardwired to that router, a MFP to a wireless LAN?

What is otherwise the advantage of a Wireless Bridge?

Hans

[Vulkor]

Rephrase this please?

Some prefer Router IP Network to be Separate from the wireless. This you can add a wireless Access point or an wireless Router in bridge mode. Thus creating a different IP Range. Though if your MFP is on one IP Range the other IP Range can't see it unless there is some sort of RIP routing configured.
MFP can have wireless bridges added to them so they can connect to a network wirelessly. I don't recommend it cause it is slow.