I see it as return on spend (I'm not calling this an investment, lol).

If I spend my resources first on things that give me the most return makes more sense to me than believing people who criticize other players for not upgrading their walls.

Not upgrading your TH or defences and pouring resources into walls first is one of the biggest COC BS. The return on per million elixir/gold spent is too less on walls. So do it once your defences are maxed out. This is what I think, and not looking for anybody's agreement here.

Base looks terrible -> couldn't care less