You're overreacting there a little....
I don't see a love in for Maguire, even from that poster's post. The argument for triggering Maguire's extension is sound. You have a manager who plays 3 at the back, you have all of Evans, Lindelof and Maguire potentially leaving in the summer on a free so no money coming in for them. That leaves us with only Yoro, De Ligt and Martinez as CBs. We also will likely have a limited budget and clearly reinforcing our attack and buying actual wingbacks is the priority. So rather than having to potentially on top of that buy 2/3 CBs, we can instead maybe bring in 1 CB and keep Maguire (and /or play Mazraoui there) for an extra year who whether you think he is good enough or not is a good backup player at the very least.
This isn't about renewing Maguire or keeping on old/poor players past their expiry date. Its prioritising where we spend our money, extending Maguire for a year helps address the number of CBs we have, doesn't tie him down to a new 3/4/5 year contract and allows us this summer to focus on the more pressing concerns e.g. finding quality Wingbacks, new attackers, a midfielder, backup GK all of which are more pressing than Maguire and all of which likely has to be done by selling the likes of Rashford etc which will still likely not give us loads of spending capability.
So yeah, you're overreacting a little to them triggering his extension.