There's absolutely nothing wrong with footer links per se. It's just the fact that it's an inconspicuous part of the site, so SEOs have thought it was an easy place to sneak in some good links.

One example that I have (I won't dive into the details too much), is a competing SEO company in my local. He has the most SEO-friendly name you can could imagine, and he tosses his SEO-friendly/anchor text-rich name into the footer of all the sites that he works on. His link profile consists of almost all blog comments and these footer links. He ranks super high for 'SEO big name city', when there are clearly much, much more authoritative sites that should be showing up ahead of him.

So you definitely can't say that search engines are discarding the value of footer links.

What I'd recommend is a 'tiered bidding' approach. Don't use different ad groups for different match types.

With tiered bidding you're setting different bid amounts for different match types - specifically, your exact match is the highest bid, followed by phrase and then broad. So it would be something like this:

[red shoes] - $1

"red shoes" - $0.75 (3/4 the price of the exact match)

red shoes - $0.50 (1/2 the price of the exact match)

This strategy  helps ensure that you're paying a fair value for all different types of search queries that are bringing traffic to your site.

Assuming that in this example, you're an e-commerce site selling red shoes, we'll argue the term 'red shoes' is the most qualified search query available. As such, you're paying top dollar for that keyword - $1. (I know your actual CPC isn't your bid price, I'm just saying - for illustrative purposes). If a user searches for, say, 'shiny red shoes', your phrase match keyword will be triggered, and you'll pay $0.75. You're paying a little bit less because, let's say, your shoes aren't exactly shiny, but there's still a chance that user will convert. Lastly, if the user types in 'what are red shoes', your classic informational type of search query, your ads won't be triggered by the exact or phrase match version of the keyword, but they will be triggered by the broad match, and you'll pay $0.50. You pay the least amount for this search query because this doesn't represent a very qualified visitor for your red shoe, e-commerce website.

Hope that helps.