It's not a battle of good and evil, it's to do with filling you needs within a budget. Some have the need for certain features or the budget to get them even if they don't. I'll be the first to admit I don't.
As a casual, fair weather camper, getting two 20a MPPT controllers for the price of the MS 15 meant I could run both of my $50 CL panels. Twice the power was more appealing than features that MIGHT be useful IF one panel or even solar would work for us at all. Then they would only be useful IF I mounted that one panel AND left the battery in the rig all year. That's a lot of ifs to run a $50 panel.
Buy what you need, over buy if you can. For those that can't or don't want to over buy, there is a option.