Your statement can be rephrased as "nobody likes their share of the pie to be decreased".
I can rephrase it further: Bitcoin users don't like their share of the pie to be decreased in some obscure way.
They don't like any departure from the 21M bitcoin limit. Which makes perfect sense.
--snip--
Exactly. Changing total Bitcoin supply would make Bitcoin immutability questionable. And if the community let such major change happen, IMO it's just matter of time before another major change happen.
I will get to Monero's case. There, iirc, there's "no" block size/limit.
Wrong, what they have is dynamic block size. It also has minimum and maximum allowed block size limit.